Skip to content
UAP LEDGER
Department of War

DOW-UAP-D097: Project Sign Progress Report, 1948

Released: July 10, 2026

This file contains an initial report from the Air Materiel Command regarding Project Sign. Project Sign was a 1948-1949 U.S. Air Force program to invest…

Full Document Text

Text extracted directly from the source PDF. Text extraction via abigailhaddad/ufo-releases; original file at war.gov.

Read the full text (200,000 characters)
--- PAGE 1 ---
I
    •
                                                        •
                                                                             Authority:
                                                                            NND927545


                                         HEADQUARTERS
                                    AIR KATERI BL COWAND
                                                                MClA/JCB/amb
                                                        Wright-Patterson Air Force Base
                                                               2DjytAPH 0i948
        KCIA


               SUBJECT,    Projeot "BIOi" •


               TOs        Chief of Staft
                          United Statea ilr Poree
                          Waahington 26, D. Co
                          ATTN s Director ot Int-,lligenoe



                    l. Thie ie an initial report on unidentified flying objecta aa
               direoted by Rq, USAY letter dated SO Deoember 1947, signed by General
               L. C. Craigie, subjeot1 •r1~Jng Diaea~. Qtarterly reports will be
               submitted beginning 1 July 1948.

                    2. Ae a reeult of thia letter, Pro~ot HT-304 was a.otiTated on
               26 January 1948 and Technical Inatruotion 2185, dated 11 Pebruaiy 1948,
               wns published. Present ti.lea on Projeot •s10~• represent a oonaolida­
               tion ot reports received directly by Hq, AMC and thoee forwa.rded by
               the Direotor ot Intelli gence, USAF.

                    ~. Schedules of activities of lighted night-flying adTertising
               blimps have been secured a.nd crosa-oheoked at thi.a Headquarters to
               consider them as a possible souroe ot incident nporta.
                    4. Inoloaure l represents a tabulation am breakdoWll of all
               available reports through l February 1948.
                    5o The following ia a series of interesting observation• that
               were noted when rev19Wing the many incident 0ase11
                       a. Rigll rate of olimb, aa well aa the apparent a.bi li ty to
               remain mot1onleu or hover for a oonBiderable length of tiu o
                        bo The objeot was described aa being oval, d1ac or 1auoer-        t
               ehaped ~l times.

                          o. Assooiated sound was preae?It ll tim.H o
                          d. Reported sizes have varied from that of a 26-oent pitoe
               to 260 feet in diameter, and from the aise or a puraui t plane to tht
               ePulk of six B-29 airpl.&nea.
,




                                       NND 927545

--- PAGE 2 ---
..
     AMC
     Subject,    Project "SIG!i"
                                                           •             2 3 APir 1948
                e.   »umber of objects per aighting,
                     Objects per sighting           l      2-6     6-10      over 10
                     Number of eightioga           77       21           8        9

                t. Exhaust traile were reported 23 times.
              g. Speed has been eetime.ted throughout the entire range from
     very alow or hovering to supersonio.
          6. Incloaures 2 and 5 are anlargementa of photographt taken of
     Incident f40o Inoloaure 4 1s an evaluation of inolosure 2 by thie
     Headquarters. Attention 1s iovi ted to the marked aimilari ty between
     incloaurea 2 ands. and inoloaure 6. Similarity also exiata between
     inclosures 2 and 3 and oonfigur&tiona illustre.ted in inolosure 6.
           7. Representatives from tbie Headquartere visited Dr. Ining
     Langmuir of the P~sea.rch Laboratories. General Electric Comp&ny.
     Schenectady, N. Y. to discuss Project "SIGN". It was the opinion of
     this acienti st that prosent a.vai l!I. ble data does not encompass suffi­
     ci ent information to enable a positive identific~tion to be ma.deo
     Dr. :.a.n&muir was relucts.nt to consider the so-called "flying discsM
     as a reality. However, it io be'lieved at this neadquarters that it
     is possible to oonstruot a low aspeot ratio airoraft that would d~pli­
     oate many of the appearance and performance oharaoteriatics of reported
     "flyint discs~. Experts have agreed that thie would be possible through
     the intelligent application of boun:lary layer control.
                FOR THE COMMANDING GENERAL:


                                              ~Me~
     6 Inols
       l.   Tabulation
                                                            J
                                                H. M. ticC~!1.
                                                Co lone1. US&F
       2.   Photo                               Chief ot Intelli gence
       3.   Photo
       4.   Eval of Incl 2
       6.   Horten Parabola
       6.   Biology of I'lying Se.ucor




                                          2


                              ~

                                   NND 927545

--- PAGE 3 ---
Incident
      No.           Date
                              /



                                  • Hour
                                            CONFIDENTIAL

                                              Location
                                                                        -              N<>•
                                                                                     Sighted
                                                                                                Obser,ed
                                                                                                   P'rom

      1         g Jul 47            0930      Muroc ilT Field, M'uroc, Calif.          2        Ground

;     la        g Jnl 47            0930      Muroc,Air Field, Muroc, Cali£.           2        Ground
      lb        e Jul 47            0930      Muroc Air li'ield, li&uroc, Cali.f.      2        Ground
      le        g Jul 47            09tl9     Muroc .lir Field, lluroc, Calif.          2       Ground
      ld        g Jul 47            1000      lmroc Air Field, Muroc, Calif.           3        Ground
      le        g Jul 47            1000      Uuroc A.Lr Field, itiuroc, Calif.         3       Ground
       2        g Jnl 47            1200      Muroc Air Field, Mu.roe, Call!.          1        Ground
      ~         7 Jul 47            1010      Iifuroc Air Field, Vuroc, Calif.         1        Ground
      4         $    Jul 47         1150      Area 113, Rogers Dry Lake, Muroc         l        Ground
                                              Air Field, Muroc, Calif.
      5         4 Jul 47            1305      ~ortland, Oregon                         5        Ground
      6         4 Jul 47            1305      1llli.lwaukee, Oregon                    3        Grotmd
      7         4 Jlll .47          1305      Portland, Oregon                         1        Ground
      ~         4 Jul 47           1305       Portland, Uregon                         3        Ground
      9         4 Jul 47           1305       Portland, Oregon                      undetermined wt atated
     10         4 Jul 47            2004      Roi se, Idaho                            5        Air

     ll         4 Jul 47          not stated Seattle, Xashington                       l        r.:.r ound

     12         4 Jul 47            1305      Vancouver, Washington                  20-30      Ground
     1~         4 Jul 47           1400       Portland, Oregon                         4        Ground
     14         4 Jul 47           16}0       Portland, Oregon                         1        Ground

     15         4 Jul 47           1700       Portland, Oregon                         3        Ground
     l.6        4 Jul 47            ll.00     Mount Jefferson near                     4        Ground
                                              Redmon, Oregon
     17        2ll. Jun 47         1500       14t. Rainier,    a.shington              9        11r
     l!S       not stated not stated Toronto, Canada                                   1        Ground
     19        20 Oot 47           1320       Dayton, Ohio                             2        Ground
     20        20 Oct 47           1100       Xenia, Onio •                            l        Ground



                                             CONFIDENTIAL
                                                 NND 927545

--- PAGE 4 ---
CO~FIDENTIAL e
Incident                                                                   No.                        Observed
 No.         Date           dour        Location                         Sighted                        From
 21        29 Jun 47        1645        Des Moines, 1owa                    l~                        not stated
  22       21 Jwi 47     about noon Spokane, ·1ashingt,on                                             Ground
  23       30 Jun 47        1745        Boise, Idaho                        1                         Ground

  24       12 J\111 47      1&5         Weiser, Idaho                        2                        Ground

  25        4 Jul 47        2345        Vfest Trenton, t~ . J.               l                        Ground
  26       10 Jul 47 not stated Harmon Field, Newfoundland                   l                        Ground

  ~        10 Jul 47        ~           Hamon Field, bewfoundland            l                        Ground

  2g       24 Jun 47 not stated Idaho                                        l                        Ground

  29       23 Jun 47 not stated Bakersfield., Calif.                        10                        Ground

  30        7 Jan 4!        l ~ T Lockbourne AB, Co1umbus, Ohio              1

  30a       7 Jan 4g        1925EST Lockbourne,!B, Columbus., Ohio           l                        Oroum

  30b       7 Jan 4a        1915EST Lockbourne AB, Columbus, Ohio            l                        Ground

  30c       7 Jan 4g        1940        Lockbourne il, Columbus, Ohio        1                        Ground
  31        mid-December early a.m.        Northern Arizona                  l                        Ground
              1946
  32
  32     not stated      after dark Columbus , Ohio                          1                        llr

            7 Jan 41! 133&.l'T,OO"' Oocbnan Field, Ky. (south of)            1                        Ground

            7 Jan~          l4000ST Godman Field, Ky.                        1                        Ground

            7 Jan~          1320CS'J.' · 0odman Field, Ky.                   1
                                                                                                             .
  33c       7 Jan 4g        J..420 CST 2100 from Oodman Field, Ky.           1                        Ground

  33d       7 Jan 4a                    Gedman Field, Ky.                    1                        Ground

  33e       7 Jan 4g J..430-1600        Godman Field, Ky.                    1                        Ground

  331'      7 Jan~                      Godman Field., Ky.                   1                        ~
                                                                             l ,l -
                                                                                      l       ,

  33g       7 Jan~ 11!54-19()6          lladi.eomi-1.le, Ky.                      ~                   Ground
                                                                                 I.


  34       13 Oct 47        05}0        l4 mi1es north of Dauphin,
                                        J.lanitoba, Canada                   ~                        Ground

  35       12 Nov 41     GQ'l.Jr a.m.   ticonderoga at sea (40 miles                                  Boat
                                        south of Cape dlanco, 20 miles
                                        o£f shore)                                        \
                                                                                              \   \
                                                                                                  I



                                   CONFIDENTIAL
                                           NND 927545

--- PAGE 5 ---
.
    DIOIDD'f
                ;w.
                                 -       vu~FIDENTIAL
                                                                                     lo.           a...nect
                                                                                                     rra
     Is,                       12111:.       r,ooat1cm                               SMaatfd
      ,6       Jot Stated lot Stated !oilt, Idaho                                          1       Ground

      ,1       12 oot 47        1200         Oa•• Creek, Ar1■ ona                          1       Qro\md

      ,s       10 Jun 47     lot Stated !udape1t, Bung&J"1                                 1       Ground

      ,9        9 Jlll 47       2,,0         Onnd Palla, levtoundland                      5       OJ"ound

      40        7 Jul 47        1600         Phoenix, Ar11ona                              1       Oroun<S

                                                                                           1       Qro,md
      •n       11 JUl 47     lot Stated lltndort J1eld, llatlta
      42       12 lUl 47        04,0'L       BltndOl't J1eld, Alatll:a                     1       Oroun4
                                         I
      43       29 Jun 47        1645         Clll"1on, Ion                             18          Oro\lDd

               28 Jun 47        1~,          Roekt1tld, W1■cou1n                      7-10         Ground
      "-5      28 .Jun 47 Afternoon n11no11                                           7-10         Ql"0\1DC2

      46       22 Jun 47        11,0         Ortent1eld, 1111,                             1       Ground

      47        6 Jul 47 lot Stated 1a1rt1tld-6uilm Air S.le, 01111.                       1       Oround

      48        7 Jan 48 1920-1955 V1la1Jllton, Ohio                                       1       Ground
                      .
      48a       7 Jan ,s        1925         111111.ngton, Ob1o                            1       Ground

                                1910&ST V11111ngton, Ohio                _,,,.,.•          1       Qrowu1
      481>      7 Jan 48
      4&        7 Jan~          19,0         Y1la1Dgton, Ob1o                              1       Orcnmd

      -84       7 Jan 48 1920-1950 111.111ngton, Ohio                                      1       ll'ound

                9 Jan 48     2,00-2,15       J>aJffi 11e , ltntllolq                       1       Qroimd
      ~

      50       10 Jan Ji8       2200         11lcSVood, In Jei-■r,                  One at tb11 Orouad
                                                                                    date, PNT-
                                                                                    1wa17 1 ..oh
                                                                                    27 Deo,, JUI
                                                                                    all at 2000 o 1oloek.

      51        'Sept lf        1215         on.ao, oneon                             12-15        Ground

               29 Jul 47        1450         1181111 ton 11eld, Cal1torn1a                 2       Oroad
      52
      ,,.      29 1111 •n Atter 1200 llllilton Jield, ca11tarn1a                           2       Ground

       53      28 Jan IJ7        1515        Lake Jllead, ore1on                           5~      Air

                                 22:50       Jorth Sea (50 ail•• troa                      1        Air
       54      16 Jan IJ7
                                                  tbe Dutch coa,t)

                                             BIJ'llCffl Pield, ltvtoundland                    l    Orolll\d
       55       2:, Jul 47       o,45Z

--- PAGE 6 ---
IAo1c1ent
                              -       -CQ~F~DENTIAL
                                                                  -         lo.
                                                                        simaa
                                                                                      Ob1enec!
  ?fe,        15a.           us.        Looat1on                                        D:99
  56         6 Jul 47        2945                                          1-10       Gi-oan4

  57        20 lul 47         0015Z     Abou-c! the BUl'aeo (at sea         1         Boat
                                        one hr. troa 874ne7, Autft11a)

  58         4 Aug 47        BYeJWII    Bethel, Alaska                      1         Ail"

  59        14 Se»t 47        055ae1T   Reeter Ialand                       1         ill'

  60        10 Jul 47         1000      Oor4707, Canac!a                    1         OPOUDCS

  61         8 Sept 47        22:,0     Salt Lllce Cl tJ, Unb              12         Ground

  62         8 Sept 47 22:S0~:S00       Salt Like Cit7, Utah             5 Sl'0'QP8   Ground
                                                                         eaoh oan-
                                                                        ta1D1Dg
                                                                        :S5~0
                                                                         01:tJecta.

  6:s       29 JuJ. 47        1205      can,on 1em, llontana                l         Ol'om:ad

  64        19 Aug 47         2130      Tv1n Jalll, Idaho               A.pprox.      Ol'oun4
                                                                           55.
  65         2 Jun 47         lot stated Rehoboth Beaoh, Delevan            1         Ground

  66        10 Aug 47         2100      811Yer 8pr1.ngt, Ohio               l         Ol'ound

  67        llJ. Aug 47      1600       Placemlle, lalitornia               1         Ground

  68        24 Jun 47      Hot 1tattd   Cuoa4e lountaiJ:aa,                 6         Ground
                                        Pwtlan4, 01-egon
  69         6 Aug 47 22,0-2245         Ph1l.a4elph1a, Pa.                  1         Ol'Ound

  70         6 iug 47         1045      Ph1lt4elph1a, Pa.                   l         Ol'oand

  71         8 Oot 47 lot 1tatecl       Laa Vega■, leYa4a                   1         Ol'Ound

  72        lot atate4 Jot 1tatec1      Port R1obardl0J1, Alllb             1         Ol"oand

  7J         4 Aug 47         1600      Boston (101111e1 n) •••·             2        A1r

  74        24 .JW'l 47 App. 1500       •t. A~IU, ftlh!ngton          lot stated      Ground

  75        1, Aug 47         1300      saote Rl•er aaix,on, Idabo           l        Ground

  76        1:5 Aug 47 Jlornlng         Salaon Du, Ic!aho                    2        Ornnd

  77         :S 11117 47      1s,~      South BrookYille, Dine             10         Gl'O\IDl2

  78        :,o Jun ~7      0910 JIST   Oran4 ClllQ'on, AP1aoaa              2        ill'

  79           Apr 47       1100 ES!    R1oba0nd, V11"g1n.1a          1, other■ on Grcnmd
                                                                      other ooou1ona

--- PAGE 7 ---
coNriBcNTIAL
lno1dent                                                                      Jo.      °'8tl"Ytd
 19,            em..                     Looat1op                            SUhtn       rrw
  80                                                                              1   Ground
  81        7 Jul 47          0900       Biokaa Jield, lava11                     1
 82        171117 47 2030-2100           0klahOllll CitJ, OklahOJII               1   Ground
 83         9 hl 47           1217       Bo1 ■t (Between Boise and                1
                                         hr1d1&n) Idaho
z, 84       7 Jul 47 l:500•140<Bft Lakeland, Jlorida                           5      Cll'ound
 85                           1200       Portland, oregon                     10      Qromd
 86         6 lulJ ~7 lot ■tated         Hollywood, Cal1tonia                 l       Qro,md

 87        lot ,tated •ot 1tated         HabMrbi1hopehiOJ1 {20 mile,           1      Ground
                                         zx, r tb ) Go rm.any

 88         S J.ug if     Atternoon      Baokenaaok, a. J.                    l       Ground

 89         6 Jul 47          lS45       lanaae City (100 miles west),        l       Air
                                         Ke.neaa

 90        29 Jun 47      1500-15:SO     Lae Cruoe ■, !low Mexico             l       Groun4
 91        28 Jun 41      2120-2146      Maxwell Pield, Alabama               1       Ground
• 92       lg Jun 47      l2l5-1Sl6      Colorado Springe, Colorado           l       Grcrund

           ll Jan 48      l    1650      Harttord, Coumot1cut                 l       Air
           !O Deo 47           l926PSf   Between Great l'alle, Montana        l
                                         and Pairfield, Ca!1tornia
 95        SO Dec 47           l926PSf   Rosedale, Oalitornia                 l       A.ir
           SO Deo 47           1926      Lov•look (30 m1lea weat), leTae1&    l       Ground
 97        30 Dec 47           1926PST Between Medtord and •t. Chaata,        l       A1r
                                       Oregon

 98        2    l(oT 47        Daybreak Houston, Texas                        l       Ground

            ~   Jan 46         lot stated Vasea, 11nland                      l       Ground

100        5 Jan 46            lot 1tated   Pretaraa&rl, F1nla1'ld            l       Ground

--- PAGE 8 ---
Incident
  No .
           Observer ' s
           Occupation
                          •         Jo1aneuvers                               Heatner

  1        1st Lt, UJAF             1lone - horizontal fl1gnt                 IiOt   stated
  la       :,/::,gt,   0::i,v'      1"ot stated                               .,ot stated
  lb       Uninown                  t-:et stated                              l1 ot stated

  le       s/sgt, USAF              Not stated                                ~!ot stated

  ld       Pfc, USAF                Flying in tight circle                    !fot stat'3d
  le       ~fot stated              Horizontal anrl tipht circles             !lot stated
  2        :Uaj, USAF               Descended from an intennediate            Not stated
                                    altitude in an oscillating
                                    fashion almost to the ground,
                                    then started climbing again to
                                    a very high altitude and moved
                                    off slowly in the distance.
   3       liajor, USAF             Oscillating in a downward twirl-          Not stated
                                    ing movement

  4        Capt, USAF               Falling at three times the rate           ?!ot stated
                                    of a parachute
   5       Patr olman, ?ortland Dippi nP, up and down in oscillat-- Not stated
           Police Dept.         ing motion
  6        Sgt, Oregon Police       Following each otner                      Clear with little
                                                                              or no cloud f orma­
                                                                              tion

  7        Patr olman, Por tland Not stated                                   Clear with little
           Police Dept., former                                               or no cloud forma­
           Air Force pilot                                                    tion
           Patrolman, Portland Str aight line formation; last                 Clear with little
           Police Dept. Pri­   disc fluttered very rapidly in                 or no cloud for.na­
           vate pilot          side-way arc                                   tion

           Patrolman, Portland Strai~ht line fonnation ; last                 Clear with little
           Police Dept . ?ri­  disc fluttered very rapidly in                 or no cloud forma­
           vate pilot          side-way- are                                  tion

  9        Capt., Harbot pilot      Discs wo'.lld oscillat e and SOl11131-'   Not stated
                                    times a full disc would be vis~
                                    ibl e, then a half-moon shape,
                                    t hen nothing at all




                                 CUiqfiDE~~TIAL
                                    NND 927545

--- PAGE 9 ---
Incident
 •oo
           ObaerTer' s
           Ocoupad.on             Ka.neunra
                                                         •          Weather

  10       Capt, United Airlines Straight-away horizontal flight    lot stated

  ll       Coast Guard            Horizontal flight                 Kot stated

  12       Deputy Sheriff         Mot stated                        Not stated

  lS       !lot stated            Not stated                        Bot stated

  14       Sot ste.ted            FUppi ng around                   Mot stated

  15       Jot stated             Not stated                        Iot stated

  16       Mot stated             Hot stated                        Mot stated

  17       Private pilot          Straight horizontal flight        Clear as crystal

  18       llot stated            Horizontal fli ght                Clear

  19       Farmer                 Straight course - were flying     Cloudless and
                                  about a city block apart. one     sunny
                                  behind the other

  20       lot stated             Straight course                   lot stated

  21       lot stated             Single file                       Rot stated

  22       Wot stated             Flashing                          Bot stated

  23       !lot stated            Horizontal flight                 •ot stated

  24       lot stated             Shooting up and down              Clear

  25       Not stated             Hori&ontal flight                 Bright moonlight

  26       llecba.nic             lot atated                        Not stated

  27       TWA Representative     llot stated                       Clear

  28       Lt Governor            lot stated                        Kot stated
  29       ffest Coe.st Pi lot.   Bot stated                        lot stated
           7000 hrs.

  30       Ca.pt. USAF. Asst      Climbing and descending ver-      Solid overcast
           Operations Officer     tioally
                                                          0
  30a      VHF/DJ' Operator       Hovering, made three 360          Overcast. 1000 ft.
                                  turns around one place. Moved
                                  to another position and circled
                                  more. Turns required 30-40 seo.
                                  Diaaeter estimated at 2 miles.

--- PAGE 10 ---
- cor~FIDENTIAL
Incident   Observer's
 loo       Occupation             Maneuvers                         Weather
 SOb       Traffic Air Controller Bobbing up and down               Overcast
 30o       lot a~ated             Climbing and de~oending           High overcast
           Profe11or and Bead     Mone                              Clear
           or Aero Kn.gineering
 32        Lt, USAP               Bone                              Overcast
           T/Sgt, USAF            Jone                             High acattered olouds
                                                                   Visibility unlimited.
 33a       1,it.,Lt, USAF         Bone                             High scattered
           PFC                    lone                             lfot stated
 33c       Capt, USA1             Kay have been turning            High overcast
                                                                   with BIS
 33d       Capt, Us.Ar            None                             High ecattered,
                                                                   vi ei bi li ty unlimited
           Col, Ky. State Police Kone                              Clear
 3:Sf      Capt, USAF (Plight     Not stated                       .Not stated
           Leader •a 869)
 :S3g      Unknown                Mot stated                       Not stated
 34        Judge                  Bone                             Clear
 35        Second Officer.Wavy    Mone                             !lot atated
 36        CAA Official           Sot stated                       Rot stated
 37        Pilot                  Kone                             Clear ..,-.'!
 38        Hungarian Peasants     Not stated                       !lot stated
 39        Constable                                               a.tVU.   ~   d
 40        Not stated             Spiraled downward f'rom 5, 000   Cumulus clouds
                                  to 2,000 f't am then went
                                  upward at a 450 angle

--- PAGE 11 ---
41 (;J~iadJENTIAL                 e
Ine14ent   Obaenv'•
 lg,       QoogtS,on                •entuur•
 1'1       Colonel. USU           . lot atated
 42        . .jor, USU              Jo\ atated
 4,        Bua Dl'"1"1"             lone
 "4        lot 1tated               lone                                 Jot ltated
 IJ5       lot 1tated               lot 1tated                           Jot atated
 46        Wot 1tat.d               lone                                 Cloud Nnb.

 ~7        Captain, usu             lolled frOII 11a. to lid•            Jot ttate4
 48        KaJor, USAJ              uoerMlillg 1na deNen41na             lot atawd
 48a       !/Bgt                    Up and down and 114• w lid•          Cold and eleu Wi'll
                                                                         t .. 11attffff 1101141.
           Cpl.                     .lao•Ddtnc and 4eaoendbll            r.t&bt aoattezaed
                                                                         oloudl 1'11:la bait
                                                                         tOIIU'dl S/1.
                                    leeendina and deaoendiag ••'17       Clear nth onr•
                                     np'idl7                             eut 1Jl S/1.
 48d       lot stated               laoendlng' and deaeendine
                          ..
 49        lot stated               lone                                 lot lbttd

 50        En.1.ttlng deatan.er     Approaohil!a llhON traa Ooean then   lot stated
                                     Pile and tall 1lovly.
 51        Jot 1tated               lot stated                           lot 1tawd
 52        Capt, USU, ASS'!. Bon.aonal lett to ri&ht, ri&ht to           CltlP
           Opentiona ottieu 1•tt l i b • cuard 1n an a1Pplane
           ~      inawuotor Pilot fOl'Mtian.

 52•       lit Lt. 1n Air           SSll1lar to a ti&hter aiNNtta        lot stated
           Il•••ne• t01:1Mr          aueu.•r• llben u e ~
           B-29 Pilot                heaT1.eP 1h1p1.
           lit Lt, UW, Pilot Boruoul ftJl7 elon tCll'Mtim                lot 1tated
           Moaquito Pilot                                                lot 1tat1d
           G<JTernaent Bllplo1•• A)rupt 4atl                             Bieh toattered
                                                                         oond1\1on Tie1\111'7
                                                                         15 a.ilea.
                                    'rNTel1ng in a detillt't1t are.      lot 1tated



                                     CONFIDENTIAL
                                           NND 927545

--- PAGE 12 ---
Incident
 110.
           Ol>aeryer's
           Opomtion
                            -   IM!¥I8 £1                           Yt•Hitr
 57        Bridge Corustruct1on Bot stated                          Clear and dark.
 58        Chiet Pilot-         Not atated                          lfot auted
           Plying 1er-,1oe

 59        Pilot                Hone                                Rot stated
  60       Storek:eepel"        lot Stated                          Clear at duak

 61        Kot stated           lfone                               Wot stated
  62       lot stated           Not stated                          Cloudy
 63        Hot stated           BOYel"ing and fluttering, 1'1S1ng   Scattered aull
                                and deecendtng.                     olouda,

  64       Executive Direct-    Hor11onal                           OnNalt
           or ot Housing
           Authority.
  65       P1lot                lfot stated                         Not 1tated
  66       Lt. Col, QSC         Horizonal Pl1.g?\t                  lfot 1tated
           Sc1ent1t1c
           Branch Research
           Group.
  67       Insurance Adjuster None                                  Clear
  68       Prospector           Banking                             Cleu

  69       Not stated           Hot stated                          Not 1tated
 70        Insurance Agent      Not stated                          Clear

 71        Capt. AC Reser-,es   Not stated                          Clear

 72        A1!S1 0tf1ce1'       Not stated                          Cloud to1'118t1on
                                                                    1oattered abOYe
                                                                    10000 tt.

 73        lavigator            Not stated                          5/l.O acattered
           (Conatellat1on                                           cuaulus vith
           type ail"cNft)                                           tops at 10000,
                                                                    Y111b111ty 10
                                                                    a11H.

 74        Prospector           Standi.nc on edge and banking       Mot 1tated
                                1n the clouda.

 75        Trout Parm Oper.     Rode up and dovn oyer the hills     Mot stated
                                and hollow ot the canyon tloor.
  76       County COlllliaaioner Hot stated                         Rot stated


                                        It
                                             NND 927545

--- PAGE 13 ---
In.ctdent    Ob ■erTer'•
  Ko,        Qo9upgt109           Manemrp                          J!eather
  77         Astronomer            Not stated                      lot stated
  78         Lt, USI (P80 Pilot   lot 1t1ted                       lot ■ tated
  79         Weather r-,o7tff     Rot 1t1ted                       Clear
  80         Lt. Col. USAP        Jot ltated                       Scattered clouds
                                                                   Y111b111t7 10-12 ailea.
  81        C1T11 Service         A1oendtng slowly
            bplo,ee
 82         P1eld Bngtn,er        Bot stated                       lot stated
 83         Pilot                 Slow roll or barrel              S<ae clouds
 ~          Sign Painter          Cl1Jlb1ng                        Clear ...cattered cloud•
 85         Pl'1Tate Pilot        lot stated                       lot stated
 86         Hot 1tated            'l'm"ned a corner and seemed     Clear
                                  to roll.
 87         U. S. Army            Descended slowly and then        ~ot stated
                                  dropped in a spiral motion,
 88         Not stated            Not stated                       Not s tated
 89         Major, USAF           dot stated
 90         Administrative Asst, Not at~ted                        Clear
            Rocket Sonde Section
 91         Captain               Trave ling in zig-zag course     Clear
 92         Railroad Employees    Climbing, diving and reversal    Cle ar alld 1unny
                                  of direction whioh happened
                                  enry few aeoonds.
            Capt, USAP            Shooting toward, the eaat at     Not stated
                                  45° angle
            L~ Col, Hq, EPlf      Descending vertically - aeaned   •ot 1tated
                                  to slow down on nearing the
                                  earth
 95         C-47 orew             Not sta.ted                      Not stated
 96         Bot stated            Bot stated                       Not stated
 97         Airplane crew         Not   stated                     tiot &tnted
 98         Immigration Service   Appeared to be spinning in       lot stated
                                  its descent
 99         Not stated            Bot atated                       lot stated
10 0        lfot stated           ?lot stated                      Not ata.ted

                                                 IL
                                          NND 927545

--- PAGE 14 ---
Incident
  llo.     Color
                         •        Shape               Size                   Sound

   l       Silnr,-                Not stated          Not    stated          Mot atated

   la
   lb

   lo      S11Tery                Saucer shaped       lot stated             ■om


   ld      Retleoted the •un' •   Diac                llot stated            ltot atated
           raya

   le      Silvery                Diec                •ot stated             None

   2       Ahai.num colored       Thin metallic ob-        Puraui t eh1p     Mot stated
           1urface                jeot, unconventi on al
                                  ah11pe

   s       Ye llowiab-llfhite     Spherical           5 - 10 t't, dtaaeter   lot 1tated

   4       lihi'te aluminum       Dietinct oftl out- 50 tt.
                                  J.1m; ta> projec-
                                  tiona on upper sur-
                                  face which llight
                                  han been thick
                                  fine or nob1. Tne,e
                                  croaaed each other
                                  at intervals, 1ug­
                                  ge1ting either ro­
                                  tation or oaci lla•
                                  tion ot alow type

   5       lot 1tated             Round                .Not 1tated           .llom

    6      1'h1 ti ah-brown       Diac                 Jllot atated          Jllom

    7      J.lumima               Di1e                 Mot determined        lone

    8      White                  Dile                 Out ol light be­      !tone
                                                       fore det&iled ob­
                                                       Hrfttion •d•

    Sa     1'hite                 Diec                 Out of 11 ght be­     Mone
                                                       ror• detailed ob­
                                                       aen-at1on made

       9   Like s hiny ohro­      Di,o                 Mot 1tated            !lot stated
           aium hub cap

   10      .bot 1tated            Thin a.nd a.ooth     Not stated            Jot etated
                                  on bottoa, rough
                                  appea.rinc on top




                                     NND 927545

--- PAGE 15 ---
II~·   ,DENTIAL
Inoident
 llo.        Color                  Shape                She                    Sound
  11        ffbi t e               Saucer                Jlot stated            ~t stated
  12        mot atated             Like tlock ot         •ot stated             Low hmmdng
                                   geese                                        aound
 13         Resembled •tallic      llot 1tated           lot 1tated             l ot atated
 lt         Lin a new di••         Like a nn dime        Like .. run, di•      lot etated
 15         Sil•er                 lilot atated          lot atated            llot stated
 16         Not stated                                   Not   stated          lfot auted
 17         ltirror bri t ht       Approximately         Diameter equal to     lot atated
                                   circular. no tail     di atan ce between
                                                         outboard enginea
                                                         of DC 4:
 18         Jellow                                       llot s t ated         Not stated
 19         Reflected the 1un     Like ci ga.ra -        Jlot atated           Mom
            brilliantly           11uch longer than
                                  wide
 20         Silnr                 Round                 About 12 inches in     Mone
                                                        diameter
 21         Dirty 1'hite          Betwe.n circle        175-2 50 t't. dia:aeter Like electric
                                  nnd on.l - in­        12 ft. t hiok           motor or dy­
                                  ••rt•d aa.uc er                               nmo
22         Shiny d l nry          Slim body             Quite large
           Bri ght and sil•ery    Ral t-circle          Not atated             Not stat ed
24         Gli&tened in av.n      Too far away to       Too far away to       lone
                                  dotenune ahe.pe       dete nain. ahape
25
25         Luminous               Plying saucer -       lot atated            lot atated
                                  DO    tai l
26         lot 1tated             lilot etated          Jiot sta'ted          lot atated
27         Silvery                Citoular in shape      Same apan •• C-54    Wot stated
                  '               like a wagon whee l    at 10. 000 rt.
28         Not etated            ·eomet-11ke            Not stated
29         !lot stated           Almo1t round           lot stated            lot stated
50         White (.light)        dot stated             lot atated            !lone




                                        NND 927545

--- PAGE 16 ---
vbV~r IDENTIAL

lnoident
  No.      Color                     Sha.pc              Size                  Sound

  30&      Amber                     Round or oval       C-47 airplane         Jliono

  !Ob      Bright white to amber Cone-shaped. blunt Rnonnou•
                                 on top and taper­
                                     ing orr toward
                                     bottom          '

  30c      White lligbt)             RoWlld              Comparable 'to run-   Bone
                                                         way light

  31       White                     Not stated          lot stated            ltone

  52       Amber                     Mot stated          tiot stated           !lone

  33       Sun flashes on metal Roughly circular         At the distance and lone
           or metallic                                   altitude the object
                                                         appeared ~o be the
                                                         size of a11Ter dollar

           ffll.1 te or luminous.    Round teudi og to   Unknown - altitude    Iona
           ·rurnod to be more        be conical          a.na distance too
           red aa the aun aet                            great

           ~ot auted                 Cone. topped with Jot stated              lone
                                     red

  :53e     Si lver with shadow       Raindrop            Unlcnown - believed   lJnJcnoa
                                                         to be lar~

  53d      1'h1. te                  Round at time• -    Uneert&in because
                                     cone ~haped         of distance

  53e      lfhi. te                  Round               l/4: she full moon    lone

  33.f     l(atallio                 Bot stated          Tremendous

  SSg      "lfot stated              Cone                100 ft. high.         !lone
                                                         43 .rt. acrose

           Redish tinge               Round              Large gre.pef'rui t    Ion•

  35       Fire oolor                 Ball               liot stated            llot atatecl

  36       )lot stated                Bot stated         Mot at&.ted            Bot stated

           Reddish with blue     lot stated              S ft. from point of    lone
           background.. Black                            view
           with white baokground
  38       SilTer                Ball                    .Not ate.ted           Mot stated




                                      NND 927545

--- PAGE 17 ---
GONfHltJ'TiAL
Incident
 lo,       001or          Shape                    ~                         Soupd
 39        Phosphoru1     Ba-shaped diaoa          lot 1tated                lot atate4
 ~o        Gray           El11pt1cal                   20-,0 tt.             Ho11e like Jet
                                                                             airoratt prior
                                                                             to 1ts appell" -
                                                                             ~   .. No
                                                                             audible sound
                                                                             beai-d 11h11e
                                                                             object va1 1n
                                                                             Yiev.

 "1        Aluaim"-       Round                        3 tt. diameter        lot atate4
 ~2        OH.yilh        Balloon                      10 tt diaeter         lot 1tate4
 1'-3      Dirty 1'lite   Between a o1.role IJ1d       12 tt thiolc and      llectJ"ie Jlotor
                          an oval (ln-.erted           175-250 tt diameter   ordynaao
                          sa~er)

 44        lfot atat.d    Jlyina Saueers               Wot 1tated            none
                          (not actually des-
                          oribed as being
                          this shape)

 lJ-5      Hot stated     Rot stated                   Hot stated            Bot stated
 46        Silvery vh1te Round                         Small                 lot stated

 47        No detin1te     Bo detim.te shape           C -51'. airplane      lot deterained
           oolor top                                                         due to the noise
           ai(!e l"etleot-                                                   ot airplane.
           ed 11ght.
  lf.8     Red            PllUli.ng Red cone           Wot stated            Rot stated

  IJ.8a    Bright light     CirculU'-like a •tU'  Ve17 lai-ge cOlll)U'ed Hone
           ohangi.ne to     1n tbe ak7 only luga. to an aeroplane 11,;bt.
           red then to
           White OI" J"•llow

  48b      Red - ldltn    Cone                         Hot detel'llintd      Jot 1tated
           descending
           Red men IIO"fin8 lot atated                 Kot 1tated            lot ■tated
           then grean and
           black to red.
  48d      Yellow or tlame Rot 1tated                  lot stated            lot 1tated
           colored.
  49       Not atated     Pencil shaped ob3eot         !lot ■ tated          lot stated




                                                   t

--- PAGE 18 ---
cot~FIDENTIAL
Incident
  10.       color           Shape                     Si•e                  sound
 50         Stated aa       Referred to aa aauoer   Kot stated              Jfot atated
            queer 11.&ht.   but not stated as being
                            ot thie detinite shape.
 51        11lver           Bomd                      Not stated            •ot •tated

 52        llhite. ah1Dy    Circular like a ball      15-25 tt Diameter     !lot atated
                            en the bott011 but not
                            completely round.
 521       ■ilk mite        Bot atated                •ot stated            lone
 53        Whit.            C1roular                  36 inches diameter    Rot stated

 54        Rot atated       Not etated                Rot eta,ed            Not stated
 55        RecUab           lot stated                Bot atated            None

 56        Dia glow ot      Round                     2 :tt. d1aaeter       Hone
           light
 57                                                   lfot stated           Kot atated

 58        Blaok            Saucer (not det1n1tel7    Larger than C~4       Not stated
                            1tated •• being tbia      airplane
                            shape)
 59        Incandescent     Hot stated                Not atated            Hot stated
           11Cht without
           appreciable
           blue and no
           redd1eh tinae.
 60        Plame oolor      Diec shaped (the 11'ter   Barrel Bead, dinner   Wot stated
                            glow •de 1t look like     plate am the aise
                            a oone)                   ot a plane tl71,ng
                                                      hi&h.
 61        White ancS       Bot stated                Sue ot Pigeons        lfot 1tated
           111Ullinated
 62        YelloV1ah        Bot stated                811811                Mot stated
           vhite
           Gleuaed and      D1so (not actuall7        , rt. a1aaeter and    lot stated
           Shialered        stated aa being ot        ot no great th1ok•
                            this shape)               neaa.
 64        Color 111111ar Kot stated                  lot stated            Hot stated
           to eiectr1c 11.&ht.
 65        lot ltated       Bot stated                15 1nohea diaaeter    lot stated
 66        Bright onnge     lot stated                lot atated            Hot stated
 67        Jllutal col01"   top 1urtaoe al1ghtly      IJ.-6 tt 1n le~h      ll'ot stated
           h1ghl7 po111h- ournd-larger 1n front                 4
           ed chi-Ollium. than 1n the rear .
                                         NND 927545
                                                      :~e :O-l 1nchea    liOMflDENTIAL

--- PAGE 19 ---
flDENllAL e
Incident
            Col OJ'
                             •
                             I
                                 Shape                        UU.                  sounc1
 68        Hot stated            D1eo - appeare~ to have      30 tt d1aaeter       lone
                                 a tail.
 69        White                 lot 1tated                   Not stated           Bussing sound.

 70        Not stated            Giant til'e cracker          Kot stated           Bu11DI aound
                                                                                   not aa loud
                                                                                   aa a rocket
                                                                                   Ship.
 71        Rot 1t1ted            Hot 1t1ted                   lot atated           Not stated
 72        Silver                Sphere( nt not like          2·3 tt diameter      Rot 1tated
                                 1auoer or diac.
           Deep Gold             1111pt1oal                   15 tt long 2·3 tt    lot atated
                                                              1n length.
 74        Bot stated            Tapered lbarpely to a        ,o tt. diaaettr      Hone
                                 point in the tront end.
 75        Slq blue          Oblong like a broad rill         20 tt. lona am       Kade a
                             hat with a low crown.            10 t,. thiolr.       av1shiq sound.
 76        Not stated            Jot 1tated                   Hot stated           Lite the eoho
                                                                                   ot • aotor.
 77        Light colored         Only oonerete evidence       50•100 tt lfide.     Loud roar
                                 or tora appeared on the
                                 lett tangent ot the group.
 78        Light gray        e1rou1ar                         8 tt. diueter        Bot ■ tated

 79        S1lftl'           Bot atated                       Lu•er than a         Not atated
                                                              Pibal balloon When
                                                              obaened through a
                                                              theodolite.
 80        Retleoted vh1te       "Blob 11                  SMll ail"plane          Hone
           light.

 81        S11Yer            Large Balloon With silver Large                       lot etated
                             d11c below it, no attaebing
                        '    cables vere noticed.
 82        Proa t7 ltbi te   Round and tlat                Equal to b\11.k ot      A 1l1gbt
                                                           6 eaob, B-29 air·       mahing.
                                                           planes td th dia ..
                                                           •t•r to tluomeas
                                                           ratio ot 10-1.
 83        Black             Round                         'tVtnt,-.f'ive cent     lot atated
                                                           piece.

--- PAGE 20 ---
, .DENTIAL e
Incident
 110,      color           Ship,
 84        Sb1Jm7          Road                        lot ltated               lore~ le11
                                                                                SbJ-111.

 85        Bot 1tated      Reseabled the D5U•l.        Jot 1tated               lot 1tated

 86        Not 1tated      lot atate(!                 IOt ltated               lot stated

  87       Jot S1t&ted     Bot stated                  lot ata.ted              lot atated

  88       lot stated      1lying di ec (not ao­       )lot 1t1.ted             lot atated
                           tual ly deaoribed aa
                           being ot thi• aha.pe)

                           Ro\lDd di,o ahaped object   50-60 rt. diameter       bot at&ted

           Refleote4       Unitonn with no protu­      Hot atatad               Bot 1tt.t1d
           light           berano•• euoh •• wing•
                           of an airplane

           Light           lot atated                  Not stated               looe

  92       Silver          lot ,tated                  S-11                     lloli ata.ted

           Bluish center Appeared to be a di10         Reaembled ~ shooting Not etated
           ·. rl th rod on                             at~r; however. ob-
           its edgH                                    aervera not oertain
           !ot atatad      lot 1tated                  Not stated               Not ,tated
  94
                            Not stated                 Kot stated               Bot stated
  95        Not stated
            Not st:i.ted    Hot etated                 Not stated               Not atated
  96

   91       Flaah of        Kot atat••                 Hot stated                Hot atated
            light
   98       Bright light    Ahaoat round or perhaps     2ti-30 miles diametor    lot etated
                            oval or aauoer-ahaped

                            Brightly ehining object     lot atated               Bot atated
   99       Shining
                            with long td 1

                            Wot ,tated                  lot atated               !lot stated
  100




                                         NND 927545

--- PAGE 21 ---
-COt~f\DENTlAL:-

Incident     Exhaust
                             -                                     e
                                                                   Speed          lffect on Cloud•
  No.         Trail          Heading          Altitude Ft.

   l        t:one            320°              1000-sooo rt.       ~00 mph        lot at&ted

   la.

   lb

            Not stated       liorthwest        7500-8000     ft.   ~50-400 mph    Hot stated
   le

   ld       f.ot stated      northwest         7000-8000 f't.      300-400 mph    tlot atatod

                    stated   tiorthwest        6000 rt.            300-400 mph    ~ot stated
   le       tlot

                                               From very near      Not ste.tod    llot atated
   2        tot stated       Not at&ted
                                               the ground to
                                               vory high

                             frost to east     10000- 12000 rt.    200- 225 mph   )lo-r; stated
   3        Not ata.ted

            Not stated       North of due      Under 20000 ft .    Slower than Hot stated
   4
                             east                                  lllAXimUDl speed
                                                                   or P- 80

            Bot stated       Two flying        Bo'\ stated.d       Great speed lot atated
   5
                             aoutb - S
                             flying ea,t

                              llorthweater ly Undetermined         Terrifie        lot stat.d
       6     Not stated
                              Southweat         50000 fto          Terrific -      lot stat.cl
       7     None
                                                                   faster than
                                                                   any object
                                                                   ever seen
                                                                    by him

                              South             40000 tt .          Terrific       lot atated
       8     Rone-

             Jlone            South             40000 rt.           ?errifio       Not ,tated
       8a

                              S01..-th          High over           Terrific       lot stated
       9     Not atated
                                                Globe Mille

                              Northwest         llot stated         Cruised for    Not atated
   10        !Jone
                                                                    46 min. at
                                                                    oonventional
                                                                    airline apeed
                                                                    (180 mph) then
                                                                    rapidly dis-
                                                                    appeared

                                                                    llot stated     .ttoi;   a ta. ted
       11     Not stated      OTer north end lot stated
                              ot Lake 1'o.sh-
                              ington



                                         CG."f,DENTIAL
                                            NND 927545

--- PAGE 22 ---
F1DENTIAl
Incident
 Bo.
            E:xhauat
             Trail
                            •
                            Bee.ding         .lltitude Ft.   Spoed          Effect on Cloud.a

  12       Wot atated       Hot stated       Not atated      lot • ~ d      Hot at&t.<l

           lot atated       3 west to      Did not appear    Tranlini BO      llot ,te.ted
                            eaat.  l north Tery high         taat they
                                                             •ere out ot
                                                             eight in eaat
                                                             in 2-4 aeoonda
  14       lot atated       lot atated                       JloT1ng slowly    llot atat.d
                                                             onr aandy
                                                             dletr1ct

  15       Iot 1te.ted      l beaded         High            Sot atated     lot atat.d
                            s outhea1t.
                            2 headed
                            north1a1t
  16       lfot 1tated      .lot atated      lot 1tatad      !tot atate4    llot atated

  17       lot ete.ted      north to IOUth 9500 rt.          Not 1tated     lot 1tated
                            about 17<i'

 18        Trail atreaa- aeenronr            Jiot atated     Not stated     Hot stated
           1ng out be-   weatend
           him like      of Toronto
           vapor trail
           'beh1m air-
           plane on
           misty day
 19        Lim alight         eat to east One 11.ile high    Very taat      Bot stated
           trace ot steam.
            Disappeared
           1m::nediat•ly.
 20        Not atated       Southwest       About 1500 rt.   Faat           llot stated
 21        Rot stated       ~.N.W.           1200 ft.        About SOO      lot atated
                                                             mph
 22        Bot stated       S.W. ot S.      7000 tt.         Slower than lot atated
                                                             two-motored
                                                             U1lY plane
 23        Not stated       !lot stated     5000 tt.         lfot ate.ted   lot stated
           Cloud-lie        8outheut        Very high        Very tut       Mot atat.d
           n.por - re-
           tained shape
           a.nd persiated
           tor onr an                                                                \
           hour




                                          NND 927545

--- PAGE 23 ---
CONFIDENTIAL e
      Incident
       Ho.
                 B.xhaust
                  Trail
                              •
                              Heading           Altitude Ft.       Speed          Effect on Clouds

       25        Wot stated   Bast              High               Fast           Not stated

       26        Bluish-black Not sta.ted       Bot stated         llot stated    Cut a clear path
                                                                                  throup cloud•

        27       Bluish-black Not stated        10000 ft.          Fast           Seemed to out
                 15 mi. long                                                      0loud1 open

        28       Not stated   Not stated        Not stated         Did not        Bot stated
                                                                   moveo
                                                                   Seemed to
                                                                   go below
                                                                   horizon
                                                                   with rotation
                                                                   of earth

        29       Not stated   10 flying      High                   300-400 mph    Bot ate.ted
                              north; on
                              reverse course
                              there were only 7

        30       None (ap-    West               3000               Slow           Bot stated
                 peared to
                 ha.ve bluish
                 streaks out
                 t'rom aides

                 Five times    1200              Prom .,ery near    500 mph        Jlot stated
..'              length ot                       g?'Ound to 1000 rt. a,tter 1 t
                 object                                               atartecl
                                                                      to le&"ff
                                                                      n.e1n1ty

        S0b      Small streak 8.8.Wo                                bceeding       Bot ate.ted.
                 trailing object                                    600 aph

        300      Wot stated    Kot atated        di!teNn.~ al•      Jfotionlesa    lot stated
                                                 titudea ;
                                                                                           ~-~------
        SI       White., heavy West to eut       20000-50000 ft.    600-~00 mph Bot 1ta1;ecl • •

        32       lone          Stationary        3000 tt.           Stat1anary     "lone

        33       lone          lone visible      Unknolm            nom n.aible Ione
        33a       Jfone        210° from         Extremely high     Stationary     !lone
                               Godman Field

                  None         Not stated        Not stated         Not stated     Bot sta:t;ed




                                            NND 927545

--- PAGE 24 ---
..   Ino14ent
      Jo.
                Ezhautt
                 Trf1l         lta4w
                                         COhFIDENTIAL
                                                   uutud• rt,
                                                                     -   Sptfd      lf(n\ op Cln4f
                )lot • ••n      Apptlll'ed to be Very h11b.              Appeued lont
      ''°                       ■ tat1onaJ7 .                            to 1M
                                                                         1tat1ozw-y.

                ?lont           210• t'Poa          Uncei-tain-          Stationary.Could be seen
       ''d                                                                           throuab oi.ffU
                                GodMn Jld.          ••PJ higb.
       ,,.      lone            210• t'Poa
                                Oodllan Pld .
                                                    25000 tt.            Stationary.lone

       ,,r      lot atated      Approx. 210•        15000 tt.            500 IIPh   lot atate4
                                frt• Oodllan Jld.

       ,,s      Not ■tated      Southw■ t           ~ aile•              lOJll)h    lot atated

       ,4       llcmo         , Vest to nat         lot stated           Speed ot a lcmt
                                                                         aeteor ar
                                                                         tallinC a tar.

       ,5       81.N• ot        IOJ"tbwaterl7       Rot atated           700-900 IIPh lot atated
                tire.
       ,6       lot atated      lortbeaat           Jot atated           lot atated Jot atated

       ,1       lot 1tated      lortheut            aooo-10000 tt.       350111'h   lot ■ tated

       ,e       lot 1tated      lfa,t stated        JIOt stated          lot ■ tated lot 1t1t.d

       39       Ion•            Bait                ,0000 tt.            V0'7 ta1t lot 1tated

       40       Kot 1tated      Appeared troa       5000 tt.             ~0-600 aph lot 1tated
                                nOJ'tbeaat.

       41       Jot atated      South               lot 1tated           Great      lot 1tated

       42       lot ,tated      Borihweat           1500                 lOOaph      lot 1tated

       4,       lot 1tated      11rat group         1200                 ,oo mph     Jot 1tat14
                                S S/£, 8HOnd
                                group 1/V.

       44       lot 1tated      South               lot 1tat1d           hat         lot 1tate4

       45       Jot stated      lot stated          lot stat•d           lot atat•d lot 1tatecS

       46       Jot stated       lortbwta tff1,1    1000                 , ••tel"    lot 1tated
                                                                         than an air•
                                                                         plane.

       IJ7       Jot etated     80'1thfllterl7      10000                J'uter 11ml lot 1tate4
                                                                         •ftT aiNratt
                                                                         h• ba4 rnr
                                                                         •••n.
                 Ga1eous green 5/V llhtn 1t          Mot stated          Gained an~ lot stated
                 a11t.         lett the                                  101t alt1t•
                               'f'101D.1 t7 • NND 927545                 udt at a
                                                                         te1"1"1t1o nte.
                                          60111 1uENTIAL

--- PAGE 25 ---
n
                                          u             NTIAL
?no1dent    Exhauat
 10,         n:,11           leaflN             Att1\Jde Pt.      Spefd       Btteot on ClOlldl

  4aa      ver, tatnt S/1 llhen 1t lett lot 1tate4                Lett         Jfot stated
           emaut trail the Y1t1n1tJ.                              T10in1t)'
           llben 1IO'fing.                                        at nr,
                                                                  h1gb 1peed.
           Gl'eenlah         S/W ldlen it lttt lot 1tated         lot stated Not stated
           111st 1hen        the TlO 1n1 ty.
           deaoending.
           lot 1tatect       210 degree, lllben 15000-20000       lot stated Hot stated
                             1 t lett the Tic -
                             1.nity.
 ~d        lone              Approxblately      1l'011 4000 to    Slow         Not stated
                             due nat lalen 1t Ter1 hi&b.
                             lett the T1o1n1ty.
 49        Lon, trail        Vest               Very hi&h        lot atated lot stated
           ot Doke.
 50        Kot stated        Shor•wrd           Rot atated but Slov until Bot stated
                                                •aid to be     OTer land
                                                quite close.   then higher
                                                               speed lfbile
                                                                 leaving.

 51        Hot atated        lot 1tated         High             Hot stated l ot stated
 52        Bone              Soutbnrd           8000-10000       JCade a P-80 Hot stated
                                                                 look llke 1t
                                                                  wu motion-
                                                                  leH 1n the
                                                                  air.
                               ;

 52&       Wot stated        120•               6000             Approxiaate- Not stated
                                                                 lT 150 aph.

 53        Bot stated        120•               6000             285 aph.      Not stated
 5~        Bot 1tatecS       Borth Sea to       22000            Equal to      Not stated
                             lortolk                             or greater
                                                                 than • Brit-
                                                                 1ab Mosquito .

 55        lot 1tated        DE                 10000            Rip yel•      Not ■ tated
                                                                 oc1t7• 1tated
                                                                 to be taster
                                                                 than conyent-
                                                                 1onal airplane.

 56        •ot lt&ted        Soutb saat         2000 tt          500-600 mph.Mot atated




                                          CONF1DENTIAL
                                               NND 927545

--- PAGE 26 ---
»ioldent Bxbauat
 lo,      m11
                               •
                         lltfflPI
                                       CO~rlDENTIAL
                                               il\1'1\4• ,t.                ltt1s\ on 212'94•
 57      lo\ 1tated      DZ <,o• I ot          ,o• ott the     Jli,tl .el.. lot 1tated
                         true IOJ'th on    llor1son at         001t7, 1ta-
                         bor1.Sonal plane. an ••t1111ted       wd toM
                                           1,A 1111• rap.      taatu t:bUl
                                                               • tnoer
                                                               \,ullet.

         lot 1tattd      1/W                   1000            510 apb.       lot 1tattd
  58
         lot attted      ,50- later            9500-10000      1000 lmota     lot atat.4
  59
                         ohaJll•d to
                         1or.
  60     Liabt tlae JPrca 1/1 bead-            6000
         oolor.     1DI Eutwrd.
                                               2000-,000       raster than 1'0t 1tated
  61     lot 1tated      lorthern                              ,ua,.
  62     Jot atattd      lot atated            &e-nral         Jl1&b rate     lot 1tated
                                               thOUlud tt.     of 1peed.

          lot 1tattd     lortheaaterly         3000            TrandOUI       Jot stated
                                                               Speed.

          Jot 1tated     lortbeaaterly         lot atated      terr1tlo        Jot 1tattc1
  64
          lot atattd     Weit to la1t           1000           1000•120011>h lot stated
  65
                                                Low            Required ,-4 lot 1tattd
  66      Lone atl'a - lorth to South
          tsht '4\itt                                          1econd1 to
          1treak 11.ll-                                        tnffl 70•
          ilar to th•                                          an.
          1treak left
          by• traoer
          bullet.
          White bail lot 1tattd                 500-1000       Tnr1tlo         lot 1tated
   67
          of l■Okt.

          Wot 1tated       Southea1terl1        6000            lot 1tated     lot 1tattd
   68
          Thin 1treaJc South                    lot 1tateO      Vff"f t11t.    lot stated
   69
          of gl"e7ill\
          color.
          Bitber 1aokt 1B to SV                 1000-,000       a.oo,oo        1ot 1tated
   70
          or conden-
           eat1on laat-
           SAI 2 1eoonda.
                                                                7ooteoo         lot stated
   71     Jilt)' hav•      Southeaat then        wot atated
          been IIIOkt      t\ll"Jled and vnt
           or npor         net.
           t r • 1nttnae                    NND 927545
           ■i,eed   WI
           aiaoet wit•.

--- PAGE 27 ---
r~eE·~flAl:
Incident
 lo.
           llxhauat
            ffiil
                          -
                         Bgd1ng
                                   ~hr
                                   iiUuii i   i


                                            41t1t1»4e Pt,
                                                               •
                                                              Sp••4           Vtftt op Qlouf•
 72        Iona          South             Below 10000         'flteaendou    Jot 1tated
 1,        lone          Ba1terl7       7000                   175 IIPh       Rot 1tated
                         approxillatel1
                         110• -,netio.
           lot stated    •ot 1tated        Jlot ■ tated        Oreata
                                                              thd&ft7•
                                                              thm, n•r
                                                              Witneaaed.

 75        lone          Baat to wet       75                  lot ,tated     loi atated

 76        lot stated    Bot 1tated        4000-6000           lot atated     Jot stated
 77        lot stated    Jfortihwat(Trut) •ot stated           600-1200       lot •ta'-4
 78        lot stated    8va1&ht down.     Deorna1Jlg tr•      Inaono~nblt lot stated
                                           approi111atelJ
                                           25000.

 79        Jot atated    Batt to lfe1t     LIii    t.ban 15000 Jot atated     Kot 1tated
 80        Jone          southeast         Lesa than 500      CCIIIPUttd at lot atawd
                                                              ·1:550 IIPh,
                                                              hOWffJI IP•
                                                              pelNd to
                                                              aOTe "1th
                                                              tbt speed
                                                              ot • Jet
                                                              11.Jlcntt.
 81        lot stated    • ortlnreat        6000              lot stated      Bot stated
 82        lone          ,5t•              10000-18000        Tbree t1M1 lot 1tated
                                                              that ot a
                                                               Jet atrontt.
 8:5       lot 1tated    lot atated        11000               lot stated     lot atated
 84        lot atate4    lortbeaat         7500                lot atahd      lot 1tated
 85        Bot atated    Borth             8500                35011Ph        lot atated
 86        Jfot etated   IOJ1thard         lot stated          lot 1tated     Rot atated
 87        lot stated    Not etated        trom 6000          lot stated     lot atated
 88        lot stated    lot 1tated        200 yards          110vhig ra,-   liot stated
                                                              ?idly

 89        llot etated   Eaet              11000              210 mph        JIJot stated


                                         NND 927545

                                   CONFIDENTIAL

--- PAGE 28 ---
11JcnTIAl
Incident   Bxh&uat
  lo.       Trail            Beading           lltitude Ft.    Speed          Ureot on Cloud•
  90       One w1tneH        lor'therly         8000-10000     lot atated     lot atated
           thought be
           eaw Tapor
           traile

 91        lot stated        Diaappear ed       Great height   High rate      lot atated
                             in the aoutb-                     ot apeed
                             weat
           Jlot stated       W.at              Abon 1000       Oreat a pffd   lot • tated
                             Dropped troa      Iot atated      Ver, high      lot atatecl
                             sight on north                    Telooity
                             aide of •t.
                             Tom near
                             Holyoke. MaH.

           Green and   Deaoending Ter- Prom lSOOO              'fery high     liot atated
           blue tleaea tioally                                 rate ot
                                                               apeed
 95        Se..-eral color•     Saatwa.rd                      Very high      Jlot   atated
           ot r1..... -                                        rate or
           red and green                                       apeed
           predomin ating

 96        lot stated        Bot stated        1200-1500       lot atated     Hot atatecl
 97        Wot stated        1'ot atated       Mot stated      !lot etated    Mot atated
 98        lot stated        Jlot atated       lot at&ted      lot a tated    lot stated

 99        Mot atated        lreat to eaat     tilot stated    lot stated     llot atated

100        Grey streaks Borth to aouth         lot atated      .llot stated   lot atated
           were left in
           eky




                         .

                                              NND 927545

--- PAGE 29 ---
lfOtE:   Inc1dent f 18
         It has now been d•tini t•ly determined that both tho photograph
         and story were t. hou:, perpetrated tor publioity e.nd aooey.

         Incident #8•
         The peraon malting t he report on thil 1nc1deat was detsrainod to
         be &n excitable person, ••r/ talkt.tive, and poaseaaing a.n ex­
         a ggerated.. iugination and 1nol1ned to iJlpreaa people with his
         continuous uhatter.




                                  NND 927545

--- PAGE 30 ---
CONFIDENTIAL
                               REPORTED DIRECTIOIS OF PLIGHT




                                                                                    D




5                                                                                               I




                                                                               2Z


                                              34
    Circling 16                              s
    Straight down 5                                  • 1'he re an undetermined number ot ob­
    Directi on Indefinite 64                           jecta ware reported the minimum number
    Direction lot Stated 61                            of object& are pl ottedo Same object
                                                       reported by di !'teren t p,ople only
                                                      shown oncto
                                        NND 927545

                                     CONFIDENTIAL

--- PAGE 31 ---
,



NND 927545

--- PAGE 32 ---


--- PAGE 33 ---
eCONFIDENTIAL
                                                        •
            Identit1c&tlon ot Subjeot llatter (a, per ••Pl•)
     IIOU                       11CIT                     19 Feb 48            l

     l. Reterenoe 1a ade to th• £11&1 tann b7 llr. Rhoad•• (In.oident f,40) which
••re tonrarded tor exuination. Tb• tollcnriq data ••r• dtri·Hd. froa a atucly ot
the 1peciaen1

          a. It ia oonoludecl that th• me• ii of tne pbotogn.phio m.ture, and
1• not due to 1~rteotion1 in th• nul.S.011. or lack o1 deTel opaent in the ■ to­
tion in quHtion. Th• im.c• •xhibit1 a "tt.11" indicating th• pn,per t)'~ ot
di1to·rtion due to the tne ot 1hutter u1ed, tht apt.cl of the o'bj•ot and tht
fixed •peed. of the abutter. Thll trailing ott oontona, to th• g.ntral intor••
tS.oD gi T~ 1n th• report.

          l>. Th• nport 1tatH th• objeot na      •••n     a.1- approxiat•ly 2000 t••t
at tho t i • ot expoaure. !he obaerHl" allO report, bein& abl• to Ht oltarl1
t. oanow of •nolo1v•. !h• Tiaual aoui ty ot an aTerag• perao!lf'woulcl allow tor
thi• peroeptioa, bu't oH•te:l Illy not auoh t'\ll'ther •• 'the 1ubjeot Md low fl nal
ooutraat, being cn.y againat a C!'&T •~• It•• ou e1tabl1ah the 41,teoe troe
o&aora ~o 1ubjeot, •• Will h&Te quntlty ,fl. !he report 1tate1 tha.t a 820 oaatrt.
n.1 u,.ct, in4ioat1ng Hnn.l po111Mlli1••• ti.not tht 620 ia ooa111cle.tur• for the
•pe>oli~ a.114 width ot the til.a •• aay h&Ye mptiT•I 2t' X 2t", 2f X ~ a.n4
2-t x 4f'. The aaapl• aubaitte4 ha.cl been out and it wa1 not po11ible to Ht&blilh
the 1xaot traat dse. !be 2t x 2f' Iii• waa rul•d out, 1-anrc 2¼ x st" a.nd
i¼ x ~ . It 1 t ftre th• ro,...r, them. the tooal leqtii ot the 101 would be •••
an4 uelisg 2000 teet ... the approid.u.te aubj•ot diatanoe and the lagt dH at
1/M•, .. ban an app,onaat• ••se ot '4 t••• a, the cllagonal of the objeot.
low 1t wa ohoo ■• the latter n.lue ot a• tor t.,eal length, •• h&Te an approxi•
•te T&lue ot' &&• tor th• cliagon&l. Poln-t:1 ot meaauNaent are 1ndioated troa .
x to x on lxhibit ••••




                      CONFIDENTIAL
                               NND 927545

--- PAGE 34 ---
•




" NND 927545

--- PAGE 35 ---
•




    NND 927545

--- PAGE 36 ---
THE AEROPLAtlE
                                                                                                                                                         I
FEBRUARY 13, 194&                                                     18S
                                                                #




                The Biolo!                             of the Flying Saf cer- I
                         The Story of Low Aspect Ratio Aircraft
                                               By A. R. Weyl, A.F.R.Ae.S.




  EVERAL MONTHS AGO peo ple o n both side.. of                      the     o ther hand. the U.S. Air Force considered the matter seriQU\
S  Atlantic rushed into print wnh claims of having ob~erved
queer saucer-shap ed aircraft which new very fast . Some main­
                                                               enough to warrant inve..tigation s into the incidenis which had
                                                               been reported.
                                                                                                                        ceased
tained, indeed. tha t they had seen ,quadron\ of , uch mysterious              In the meantime. the occurrence of Flying Saucer\ ha..
ob{"ccts; others described vividly how these celestial saucers v.ere        to be new\. P resuma bly. the~ have all landed. [A new crop
ab e 10 descend vertically. All agreed on the \aucer-hl.e , hapc.           wa<; reported in Tur AER0PLANF for J anuary 16 la~t under the
   Sceptics considered that, for non-aerona utical people ltv1ng            heading •• Tuppence Coloured." -Eo.]
far from the former playaround s o f V . I. V.2, a nd all the rest                        Aerooaudc-al Aotlquities and lniquititt
of H itler's "civilizator y • practices. flying saucer<; might indeed          As a matter of fact. saucer-\hap ed aeropla ne.. are not quite
constitute phenomena of threatening aspect, from their experi­
ence of domestic disagreemen ts. Doctors, however. hastened to              as new as some people have tried to mal.e out. (Fig. I.) Quite
assure the World that saucer-shap ed or lenticular objects could            a number of a1rernft have been constructed and nown with
well be nothing more than specks in the lenses of the eyes of the           wi11gs of the ring or disc type which could well have been mis­
observers- the so-called m11sae 1·0/ames associated with high               ta ken for saucers. hat-brims. ~pades, doughnut~. diamonds.
blood pressure. Teetotallers blamed the sorry consequence.. o f             Greek letter,. pancal.e\, nat fhh. geometrical symbols. d inner
imbibing intoxicating liquors for the observation s. On the                 plates, and other entirely non-aeronau tical commoditie s.
                                                                               Moreover. it is qu ite true. .and not even a minor secret, that,
                                                                            at present. aeronautica l engineers are paying increased a ttention
                                                                            to s uch queer wing shapes: disc wings. for instance. permit
                                                                            ceriain disadvantag es of conventiona l wing\ to be overcome. It
                                                                            1s even thought that such shares have been neglected too long
                                                                               1 he blame for rheir neglect can be ascribed to the doctrine
                                                                            o f the induced drng. When the Lanche..ter-Pranc.ltJ aerofoil
                                                                            theory became recoi,1nized nearly 30 }ears ago, and \\hen the
                                                                            !>a1lplane movement proved that slender wings were a necessity
                                                                            fo r soaring. designe r, began striving a fter .. good .. aspect ratios.
                                                                            The theory blinded their eye~ agains, the poss1bili11es of other
                                                                            than convenriona l wings. T hi~. hO\\Cver. was not the fault C"f
                                                                            the theory.,\\ Prandtl soon sho\\ ed its restrictions.
                                                                                We have now come 10 reconsider the matter of wing shape
                                                                            in an objective way. as it is quite possible that aircraft design
                                                                             is approaching a cul-de-sac ~o long as it retains it~ bias in

                                                                                        - - 6 - - - -~


                                                                                                                  ==~
                                                                                                                           Apttro.l
                                                                             1
                                                                             L-- .I_              _°'
                                                                                   _ _ __ _,_ ' _'°' _1_ _ ____,, - r . : - - i , (b       I   c 6)

                           OCl5S • stCTIO!'I




                                                                                                                       \    ,pa"
                                                                                                                       C    chor4
                                                                                                                       \    )(•-,lod a,u

   Fig. 1.-" Turbine flying machine" (project) of the Munich
   engineer Gustave Koch, 189311894. Tailless monoplane of
   low aspect ratio. propelled by a ducted fan. A SO h.p.
                                                                                    t       SquHC'

                                                                                               ...~   ,
   steim engine wu deemed sufficient for th is flying motor
   car. The design of the duct shows intelligent anticipation.

   Fig. 2 (Right).- Definitlon of the aspect ratio of an aerofoil.
                                                                                    L     ...._______.
                                                                                          I- b , __j                                AR • 0-1
                                                                                                                                                      l t t
   The arrows signify the direction of the air flow against the
   wing. The terms pteroid (feather-like) and apterold have
                                                                                            ttt
               been introduced by F. W . Lanchester.
                                                               NND 927545

--- PAGE 37 ---
\   I
           THE AEROPLANE                                                         186
                                                                                                                               FEBRUARY 13, 1948
          C..HlUr of the "well-tried " convention,        .. normal " wings.
          For the c reasons. a study of. the hi\lory of the u'IC of low
          asp,.-ct. rat,o) m wing de:.11n will be of interest.
             Sp1ruually, the fathers of uch acronauucal exhibits were
          Ens!"hmen. 1 hey were people of good reputation ttnd by
         no _me.ins suspect o( aerodynamic perversion.
              F. W. Lanchcstcr was undoubtedlf the first acrodynamici ,t
         to g,~e thought to aeroplane winis ot circular or squ.irc ,hapc.
          lo ht) bool.. publl\hcd m 1907, he referred c'<prcssivcly 10 ~uch
         "aptcrold" wmii hnpc~ {F1a. 2) i,nd advanced the view tha t
          Nc11.ton's law wa, valid for these. 1he correctncs; of th i~                     Fig. 3.-A simple experiment In annular .ierofolls.
         vie\\ wa~ c~pcrimentally proved 30 ~cars later.
             In a prev1ou\ article on " Stalling Characteristic s of Taille-.s
         Aeropl.rne~ •• ( lttE AFROl'LANI:. for August IS. 1947), tl,e early
         mtcrc-.t tal..cn by F. <i:iow Sir Frederick) Handley Pa~e m the
         stalling quahucs of wmgs of low aspect rauo was mentioned.
         He showed, 10 a pap~r read an April. 1911. that marginal vortices
         and pressurc-equa lmng flow a round the tips were respon~iblc
         for the delay of flow separation which h.id been obmved at
         high incidence).
             He stated. in this connection:-•· . .. With planes of high
        aspect ratio _(I.e.. with slender wings of normal span chord
         rnllo), \here " not the same facility for the " feedmg m " of
        f_rcsh air at the plane sides (i.e .. nt the wing tips) 10 act as a
        l~nk between the plane and the live stream. and therefore the
        live stream leaves the plane's b11ck at .in earlier st11i;e than in
        the ca,e of the plane of lower aspect ratio. . . ." He then
        sho11.,ed_ some experimental evidence for the delay of flow
        separauon with decrease of the aspect ratio and for the greater                 Fig. 4.-Prlnclple or th• Huth annular-biplane system.
        maximum lift of such wing~.
           . When Lanches.t cr published his bool.., man was ju~t begin­
        nma to_spre~d his wmgs. and in order 10 fly with a minimum                   main wing. the tailless aeroplane is created. For all these
        ellpend1ture m power, wini:s of fair aspect ratio were a neccs­              arrangements. the condition is that, in the case of a wina com­
        s11y. Neverthele\s, there were a few early aeroplanes. notably               pmed of normal (unstable) aerofoil ~lions. the stabilizin&
        the little :· Demo1~lle •• monoplane o f Santos Dumont (1909-                aerofoil exens a certain leverage in relation to the centre of
         19 !0l, which had an aspect ratio of only 2 and proved to be                gravity of the aircraft.
        qu Ile \Ucces,ful.                                                              Another possibility is to combine two lifting winas so that
             One o( the earlie~t attempts at a genuine •· apteroid" 11cro­           they will stabilize and balance each other. For this purpose, all
        plane was an experiment by a German architect, Flick-Remig                   that is required is that the front wing shall possess, at all inci­
        ( 1910). It had a span of 7 j ft .. and performed in hops only.             dence, of.flight, a greater effective incidence than the rear wiog.
                                                                                     In other words. the centre of gravity must be nearer to the
                                Annular Aerodynamks                                  le.iding wing than to the traili9g wing, and the whole arrange­
                                                                                     ment must be balanced accordmgly. In this way, we arrive at
            A ,1mple experiment with ~ome paper and a pair of sci,sor;               the conception of a stable tandem aeroplane.
        shows that the ~inl..ing speed of a circular disc loaded with a                 If we now take such a tandem arrangement and sweep the
         paper clip is decreased when a hole of suff1e1ent d iameter is cut          leading wing back and the trailing wina correspondingly forward
        out in the centre (Fig. 3). This justifies the development from             so that the tips of both wings merge into each other, we obtain
         the circular d1-.c wmt; to the annular aerofoil. The theory of             an annular or ring-shaped wing system. Aerodynamica lly, it is
        the phenomenon i~ still somewhat obscure.                                   of minor importance if the shape is actually circular or oval,
            (Having tried thl\ experime01. we can confirm that the char­            or 1f triangular or quadrangular sha pes con,titute the wing. For
        acteristics of an annular aerofoil are certainly very d ifferent            ,implicity's ..ake, in all such cases considered here, the term
        from those of the plain d1-.c aerofoil. Our own experiment,                 .. annular" 1, appl ied.
        11.cre admittedly somewhat lim1ted in scope and we were unable                  As mentioned, the aerodynamics of such shapes cannot yet
        !O form more than an imprc~10n of the relauve sinking ,peed,:               be considered as fully established. But it i, proved that longi­
        II did, howev~r. arpcar to be le,~ with the annular aerofoil. Our          tudinally stable wing systems can be obtnined with such shapes.
        mam conclu\lon, w•!re that cutting a 2.25-in. diameter hole in             Some type~ relying on such wings have shown quite remarkable
        a .5 37S-in. diameter disc. resulted in a much flatt.e r glide; the         llying qualiue~. It is also pos,ible that, with annular wings. the
        ,tall 11.,1, not ,o abrupt. and the stability in the glide wa,              induced drai; i, less than with conventional wings of equiva­
        1mpm,cd. We were so fascinated with the e>tperiment th.it we                lent aspect ratio.
        hope to repeat u ,U a later date on a more ..c:1entific levcl.- Eo.)            In common with circular wing,. annular wings have the
            fhe conven11onal aeroplJne " constituted of two ba\ic aero­            remarl..able property that the lift force ,teadily increases with
        frnh: a "ing (,, h1ch ,uppl1e~ the lift) and ri tail (,, hich balances     incidence up to fairly high values without a stall. For all
        and ~tabilize~ the wing). We I.now that \Uch a n arrangement               I.no" n arrangements the maximum lift seem, 10 occur at
        o.f the 111.0 aerofoil compnnenh i, by no mean, the only pos­              incidences exceeding 30 degree,. A, ,uch h igh angle~ of
        \tblc one. The balancing .ind st11b1lmng aerofoil (tailplane)              incidence are not likely 10 be reached an flight unintentionall y.
        need not to be aft of the lifting wing a, a tail. It can be                It 1s obv1ou, "hy annular wings have become renowned for
        arranged anywhere 1n relation to the wing. e.g .. above It, belo11.        their good-natured flying charac1eri,1il:,.
        it. o r in front of it.                                                        Another property of annular wings (first establi,hed by
           If the balancing aerofoil i, in front o f the main win~. the aero­      Tilghman Richard,) i, that the centre of pre,sure of ,uch wing
        plane i~ of the tail-first type. and if it i, attached to the              ,y,tcm, i, nearly stationary in flight , or that a travel o f the
                                                                                  centre of pre,wre can be obtained which i, po,itively stable
                                                                                   unul incidences o f the order of 18 degree are reached. In
                                                                                   fact. no case of longitudmal in,tabihty ha, ever been reponcd
                                                                                   w11h an annular wing. although the centre of gravity has often
                                                                                  been located d:ingerou,ly far back.
                                                                                       The fi~t annular-wing aeroplane dates bacl.. 10 1908. It
                                                                                  h,1d little succe\\. Two type, 11.ere con~tructed m ,ucces\ion
                                                                                  tu the de,1gns of a capable German aeronautical engineer, Fritz
                                                                                   Huth. who "as by profe\\1on a teacher at a technical ,;chool
                                                                                  ( f-tg,. 4 and 61. The ,econd type. which had a less elaborate
                                                                                  a1r,crcw drive. flew in May. 1910: it wa,. however. ,o devoid
                                                                                  of performance. in spite of a SO b.h.p. engine. that it was soon
                                                                                  ,1f1erv.ards d1..carded as a hopeless proposition.
                                                                                                Britain'~ Fir..1 Doughnut
                                                                                The Bri11,h concepuon of the idea has been for more
                                                                             ,ucccs,ful. A, it i, cun,1i1u1ed, until now. the best tried
                                                                             reprc,cntativc. it~ hi,1ory may be given somewhat more
                                                                             c,1cn,1vcly.
                                                                                Ihe ori~mal idea for an annular-wing aeroplane came from
                                                                            (,. A K itchen. m about 1910; he con,tructed a b1pl.1ne with
                       Fig. S. Kitchen's doughnut of 1911 .                 rini:-,haped wmg,, but made no progrcs, "ith it. The stable
                                                                      NND 927545

--- PAGE 38 ---
FEBRUARY 13, 1948


                                             -
flight of K itchen's models. however. convinced Cedric Lee
that an aeroplane of such de~ign would be a succes,. 11nd late
in 1910 he acquired the patents. At the same time, G. Tilghman
Richards, who was a qualifii:d aeron:iutical engineer, became ,
~uffic1ently interested in the mailer to give up a budding
engineering bureau in order to join Cedric Lee and 10 devote
                                                                    187




                                                                                    ·JUI·             tl?,!i m
                                                                                                                     THE AEROPLANE




hib energy 10 tbe idea of a ·• safety " aeroplane.
   Tilghman Richards began with systemat ic experiment, on                                                            __.._
models and on large gJiders. Later, careful wind-tunnel test~                                                          -:'x:
(including the o bservation of the pressure distribution) were                                                             - -'-
made by him in a :!-ft. tunnel he had constructed at East London
College and al~o in tunnels-of tile National Physical Laboratory.
The preparation of the design was, therefore, uncommonly
~-ardul for this early period of 1911 - 1914.
    In o rder to ap(>reciate the intention~ for the development, the
following quota11on from a paper read by Tilghman Richards
in about 1912 is illuminating: -
    ... . . 1 he ve ry fnct of high lift occurring at small angles
rreans the provision of large area for l•nding speed resulting
in an inefficient altitude of the plane at high speed: and the
inherent instability of curved aerofoils means a continual
dependence on extraneou, controls carried at some distance
f_rom the wing by heavy and redundant Structure. . . . High
lift at small angles il> u~eles~. likewise h igh lift/ drag ratio at                   Fig. 6.-Huth annular biplane of 1909.
,mall an,les, and what is required is the reversal of the normal
type of hft c urve i:iving little lift •lit small angles with low value and Gordon Bell. Finally it came to i;ricf when flown by
of the lift/ drag ratio for landini. . . ."
    Seen from our pre.sent state of knowledge and development, Cedric             Lee himself without previous training. After a good
                                                                        fliaht he managed to put it into a river.
a nd facing the burning problems of personal aircraft for the              Another incident happened with a subsequent annular
 man in the street. it wo uld seem that this opinion is a very
 i;o~ argument for further experimentation along the lines monoplane: the elevator jammed anct broke in flight. The
 indicated.                                                             aeroplane merely pancaked to the ground, again preserving
   _The. experience with _powered aeroplanes was at first beset the health of i~ pilot, E. C. Gordon England.
 with disappointment~. Famine P_oint, Heysham, was apparently              These types in their final form had lateral control effected
 no t a spot from which aeronauucal experimenters could derive by differential deflection of the elevators. It was realized that
 any comfort.                                                            this elevon control was not very effective for lateral manceuvres.
    The original Kitchen biplane with a 50 b.h.p. rotary engine yet the lateral stability of the wing proved so great that the
 was wrecked by a gale, during I 9 I I. before flight tests could provision of ailerons seemed superfluo us. The loneitudinal
 b~ m~de. After recort~truction some flight~ were performed stability was always satisfactory, once the centre of gravity was
 wtth 11 at Sho!eham <!~ring 1911- 12: yet it never gave any properly located. Because of the great inherent · fore-and-aft
 pr~~f of superior q~ah11es. The biplane had ailerons o f the stability, a separate elevator was, at o ne time, located on top
 or1gmal Farman variety between the wings. Very soon the of the vertical fin and permitted the fitting of special ailerons.
 biplane arrangement w!1s given up in favour of the monoplane. For directional control a vertical rudder was attached to the
    A subs~quent experimental monoplane was nicknamed the stern of the fuselage at the trailing edge of the wing. A form
 " Sccret-C1rct1: Plane ". ~r "Doughnut,'' the experiments being of tricycle undercarriage was employed.
 shrouded agamst pubhclly (much against the interests of the - In respect of perfo rmance, the wind-tunnel tests indicated
 dev~lopmen!), This annular-wing aeroplane (Fig. 7) was that a better lift/ drag' ratio could be expected than with a
 equipped with an 80 b.h.p. rotary and test-flown by Gordon comparable conventionaf aeroplane., However, no co nclusive
 England on November 23, 1912. at Shoreham. The flight evidence for this has, as,yet, been presented.
was _remarkable and luck>; for the pilot, but. unlucky for the             The third British monoplane of this type also had an 80 b.h.p.
 precious craft. After havmg flown a large circuit on the first rotary engine. but this time it was located aft and. further, drove
 attempt. the pilot noticed, when coming in to land that the the airscrew by means of an extension shaft. Unlike its pre­
 aeroplane was exceedingly tail-heavy and getting out ~f control        d~cssors, ~~ dihedral was provided. and because of this the
 the elevator. bei!Jg insufficient. At about 150 ft. above th~ flying qualities were found to have been greatly improved.
 ground the inevttable stall took place: but the pilot managed From early in 1914 until the outbreak of the 1914-18 War
 ~~mehow to drop his mount upside down on to telegraph this unco nventional aeroplane was frequently flown (mostly
 wire~ and escaped without personal injury.                             by Gordon Bell): it was demonstrated before Winston
    Wtth the reconstructed and improved monoplane many Churchill in the hope of securing orders from the Admiralty.
s\iccessful flights were made by G o rdon England, N. S. Percival          Altogether, 11,000 miles were flown in about 128 hours, a nd
                                                                        eve~ people not previously trained as pilots were able to
                                                                        fly 11. In Ma y, 1914. two such aeroplanes were being designed
                                                                        for parlicipation in the Gordon-Bennett Race of 1915. When
                                                                        the 1914-19 18 War terminated the work. it had clearly grown
                                                                        far beyond the stage of an untried project and could have
                                                                        well been termed a successful experiment with every prospect
                                                                        of becoming a practical proposition.
                                                                           In l?l~-10 Tilghman Richards succeeded in persuading the
                                                                        Air Mm1stry 10 place a n order for a further experiRlental
                                                                        aeroplane. But a week after communica1ing this decision
                                                                        Major-General Bagnall-Wild, the promoter of the idea, retired,
                                                                        and red tape killed an intelligent intention.
                                                                           It is only fair to record that aeronautical progress has suffered
                                                                        fr~m the failure to have this develop'ment continued. As
                                                                        Tilghman Richards stated many years ago:-
                                                                           .. There i~ no!hing myMerious about th~ annular plane.
                                                                        It affords high ltft at large angles, ha~ no >urble point and
                                                                        has ~ good lift/ drag . rati_o for wings with a body. ' The
                                                                        !Tiachm~ was very fast in p,ght. for its day, and extremely slow
                                                                        m lan~mg: and there bei!)g three dislinct regions of lift, one
                                                                        a ptero1d and two pterygo1d on each half-wing. the movement
                                                                        of the centre of pressure was a resultant of three distinct
                                                                        regional movements; ,tnd with slight modifications could be
                                                                        made 10 move in any desired manner witho ut affecting the
                                                                        general efficiency of 1he plane."
                                                                           As _mentio ned. th«: c!rcular shape for the wing is not in itself
                                                                        ~ dec1s1ve cha".\c1enst1c. ?reviously. in 1908, A. H. Edwards
                                                                        invented the ring-type wing with rhomboidal or triangular
                                                                        shape_ (Brit. Pat. Spec. No. 4519 of February, 1908).            An
                                                                        experimental aeroplane of this type, "The Rhomboidal,'' was
                                                                        constructed and tested at Brooklands. It wa~ not s uccessful.
  Fig 7.-Cedric Lee Monoplane No. 1 of TIighman Richards, 1912.                                    (To ~ conlit1u~d.)
                                                                 NND 927545

--- PAGE 39 ---
.. ,.
..
             MARCH S, 1948
                                                   -­                         279                          -                 THE AEROPLANE


                          The Biology of the Flying Saucer- II
                                                     By A. R. Weyl, A.F.R.Ae.S.
                          In this series of articles the history of low-aspect-ratio aircraft is recounted and
                          technical aspects of their design discussed. leading up to their use for supersonic flight.
                       (Continued from J>Olt 185, February 13 /rut.)            qualified aeronautical engineer (Fig. 10). The Willoughb}
             THE SECR ET-CIRCLE "CONSPIRACY;• mentioned pre­
             viously in connection with circu)ar-aerofoil aeroplanes. did
          not lack congenially inventive spirits. Early in 1913 an engineer
                                                                                Delta Co. of London had taken up the development of th,.,
                                                                                 idea in 1931 and sufficient means were available to make rather
                                                                                extensive tests.
          in D ijon. M. Bou rgoin. made experiments with an annular­                The principle is best described as a tandem monoplane with
         wing aeroplane. The tests were unsatisfactory. One feature             two aerofoil-shaped parts connecting the leading wing with the
                                                                                trailing wing near the tips. The "side wings" had aerofoil
         of this design was the provision made for varying the wing             shape not only in their longit ud inal cross-section (i.e., in the
         incidence in flight.                                                   direction of flight). but also laterally. This was considered a
            More recently, a similar idea was suggested by N. H. Warren         characteristic feature and subject to patents. It was claimed
         and Th. R. Young (Fig. 8).          In 1937 they secured a p atent     tha t the vortex distribu1ion induced by such shape gave an
         ( Brit. Pat. Spec. No. 508,022 of December, 1937) for a non­           unusually h igh aerodynamic efficiency in spite of the small span
         stallable monoplane of rhomboidal shape (i.e., leading wing            of the aeroplane. In addition. it was pointed out that the
         swept back and trailing wing swept forwards with the wing lips         maximum lift was shifted to very high incidences. Moreover.
         merged together). This was provided with a conventional tai l          the "side wings" should reduce the drag of engine nacelle,
         at 1he stern of a long fuselage and a number o f advantage~            filled underneath them.
                                                                                   All this was said to be proved by extensive wind-tunnel
                                                                               experimentation here and abroad. Designs of passenger trans­
                                                                               po n aircraft reaching weights o f 40,000 lb. were prepared on the
                                                                               basis of model tests made at the National Physical Laboratory
                                                                               a nd elsewhere. T he results must have been so encouraging
                                                                               that a n experimental monoplane with two 125 b.h.p. Menasco
                                                                               e ngines and weighing 2,540 lb. was constructed late in 1938
                                                                               (Fig. 11). This aeroplane flew indeed and was even publicl~
                                                                               demonstraled (including one-engine flight) a1 a Garden Party
                                                                               in May, 1939. Shortly afterwards the experimenter was killed
                                                                               in an uneitplained c rash during a flight test.
                                                                                   From pressure plots over the "side planes" which have been
                                                                               published, apparently trim changes could be eitpected at various
                                                                               aocidences. These components were thus capable of producing
                                                                               long itudinal inslability a nd it is not improbable that this and
                                                                               poor control efficiency may have contributed to the accident.
                                                                               There was a lso evidence of a stall at normal incidences.
                                                                               although of a very mild character and with little apparent
                                                                               decrease in the lift c~fficient (which. however, would not
                                                                               exclude the presence of fl uctuating lift forces).

                                                                                                                        11




             Fis. 8.-Project by W arren and Young for a liJht twln­
             en1lned two-seater of 90 h.p. (1937). The elevator is
              fitted between fin and fuselage. There Is no tailplane.

        were claimed. lo 1943 a model for a two-seater fighter with
        tail turret show~ the separate tail omitt~d; special emphasis
        was laid oo the triangu lar shape o f each wing and the effect of
        sweep was relied upon. N othing more bas become_ known
        since however b ut it is worth noting that the proJect had
        been'based oa ;ound aerodynamic considerations.
           lo 1933 the annula r wing of the German sculptor Antes
        created a mild s~nsation bc<:ause ?f the good performance oC
        models made to th is coocepuon (Fig. 9).
          Some.what pecul iar was the aerodynamic ~onceP.tion of the




                                           =
        rhomboidal annular aerop lane of P. Nesbitt W11loughby, a                    Fig. 10.-frinciple or the W illoughby Delta design.

                                                                                 Another suggestion for an annular wing was made by L.
                                                                               Peel, in 1944.     This. however. was concerned less with the
                                                                              aerodynamic p roperties of such wing systems than with the
                                                                              arrangement of two engines facing each other with their air­
                                                                              screws. in order to overcome the torque reacuon.
                                                                                 A phenomenon of which aerodynamic experimenters were
                                                                              alwa)ls well aware. but which aircraft designers failed 10
                                                                              u1ilizc, was that wind-tunnel tests clearly proved good-natured
                                                                              stalling p_roperties of wings having very small aspect ratios.
                                                                              Yet even m the very e_arly days when centres of gravity were far
                                                                              too far back on the old box-kites, the square shape of tailplanes.
                                                                              then unaccountably in vogue, ma y have saved the pilot's bacon
                                                                              more than once by its refusal to stall under eittreme provocation.
                                                                              Later on science came and proved that a tailplane of "good"
                                                                              aspect ratio was more eflkient. It was, but it made the stall
                                                                              worse when the centre of gravity happened to be rather aft.
                                                                                The interesting thing is that aerofoils of circular or square
                                                                              shape were tested in the early days at incidences up to 90
                                                                              degrees, while o n normal aerofoils tests were restricted to rather
             Fis, 9.--Model of the "annular wing " ~f Ant es. 1933.           small incidences onl y. generally ucluding the range o f stall.
                                                                  NND 927545

--- PAGE 40 ---
THE AEROPLANE                                                      280
                                                                                                        e                MARCH S, 1948

                                                                           argument against disc wings. The best aerofoil sections in use
                                                                           prio r 10 about 1925 had a plain camber which implies travel of
              c                                            >               the centre of pressure when the incidence varies; the length of
                                                                           such travel is linked up with the wing chord. Hence the change
                                                                           in trim o r stabiluy is. with such aerofoil sections, greater with
                                                                           large-chord wings. On this consideration of fore-and-aft
                                                                           stability and control, designers bad some justification for thcir
                                                                           decision against experimenting with disc wings.           Yet quite
                                                                           useful aerofoil secuons had a lready been used in flight which
                           \         I           \     I                   had practically no travel of the centre of pressure and hence
                           I I           I   I   I I                       d id not suffer from thi~ disadvantage of the disc wing.
                               \,'       I   I       \,'                      The whole argument, however, lost its importance imme­
                                                                           diately M. M. Munk proved that very efficient aerofoil sections
                                                                           could be designed with a completely (or nearly so) stationary
                                                                           centre of pressure. It is. therefore, right to say that from that
                                                                           time all conditions existed for a practical evolution of d isc-wing
                                                                           aeroplanes.
                                                                               F. Handley Page converted an aerofoil, leaving an aspect
                                                                           ratio of 6.25, into six square-aerofoil po rtions by five slots.
                                                                           each parallel to the chord of the wing. By so doing he hoped
                                                                           to have the low drag of a oormal wing combined with the high
                                                                           stalling angle of the d isc-type wmg.            Although a very
                                                                           slight improvement was claim~d , the principle was that of
                                                                           eating the cake and having it too: the induced drag is respon­
                                                                           sible for the stalling properties of the d isc wing and you cannot
                                                                           have the benefits of the high drag without suffering its disad­
         Fig. 11.-Willoughby's "Delta 8" experimental                       vantages. Moreover, in o rder to have the effect of the disc
                        monoplane of 1938.                                  wing, the provision of mere slots is insufficient.        Marginal
                                                                            vortices need room to deploy.
                                                                               On the whole, however, the idea proves that at least one
  Thus, an observant student of laboratory tests could have                 practical aircraft designer had realized that there was some­
  noticed the extraordinary capacity of circular or square shapes           thing in wings of abnormally small aspect ratio.
  10 give a very gradual, innocent stall, an~ that at v!!rY high               There were other. although not quue as well thought out,
  incidences. Yet, a part from a few broad-minded experimenters,            antecedents of the disc-wing aeroplane.        In the tint soaring­
  no designer drew the conclusion that wmgs of such shapes                  flight competitio n on the Rhocn ( 1920), Friedrich Richter, a
  promised safety in flight, t~oug_h it w~s known f~om ..~rly               burly naval pilot o f 20 stone or so, performed on a triplane
  practical experience that fly1Dg 10 the second regime, 1.e.,              glider with wings having an individual aspect ratio of far kss
  at the stall, was positively dangerous.                                   than three. H. Hayden secured, in 1922, a patent for a rhom­
     It is true that spinn ing- Pa rker's "Spiral D ive "-was               boidal wing with an aspect ratio of nearly unity, claiming for
  attributed. in those days, to high i~cideoces, and that most _of          such a shape high lift and good flying qualities.
  the lightly loaded rectangular wmgs used at that period                      In 192S he constructed a glider with a win, having an aspect
  rendered the stall relatively. in nocuo us.    Howeve_r, :iccidental      ratio of only 2.25. The wing was nearly tnangular in shape,
  ~tailing was then, as now. the cause of the maJonty of all                with its apex leading, and a pronounced wash-out towards the
  crashes. And the nose dive following inadvertent stalls was well          tips (Fig. 12); no lateral controls were fitted. The tailplane
  known to be o f the most serious consequences.                    .       with the elevator was fitted underneath the trailing edge at the
     Eiffel, Riabouchinsky, D ines, . Prandtl, etc., began the_1r
  laboratory experiments on aerofoils of very small aspect rauo
  and the results were generously published (how closely secret
  they would be kept to-day!). Eiffe l showed that the ratio of
  the resultant forces reached maxima for small aspect ratios _an~
  that slender wings gave the greatest drag at ~ degrees 10c1-
. <lence, whilst disc wings had then t_he leas) res\stanc_e of _all.
   Riabouchinsky proved that the maximum 11ft with d15:C Wl1'!8S
  wa~ reached at incidences of the order of 40 degrees. whilst with
  normal aspect ratios (exceed ing a value of 4) the maximum lift
  took place at incidences of 12 to 14 degrees only.           Beyond
                                                                                                                  c          ==---=--
  their critical incidence disc wings gave a gradual decrease of
  the lift force whereas wings o f normal aspect ratio gave a
   very abrupt ; nd unsteady one. 1 he tests by Dines on flat
   plates in natural wind confirmed this info_rmauon and that the
  observation applied 10 cambered aerofoils as well was also
  proved (by Riabouchiosky). 0. Foeppl s_howed frof!l system­
  atic wind-tunnel tests that a square aerofoil behaves, ID respect
  of its lift curve in a remarkably d ifferent manner from one                       Fig. 13.-A French project of G. Abrial, 1929.
  having an aspec't ratio of 1.5, although wall interference and
   Reynolds Number may have somewhat affected the results of
   the tests.                                                .              stern of a f11selage. Flyinf experiments in Styria were said 10
     Later, Pra ndtl was eager to point o~t that his aer~fo1l theory        have proved satisfactory flying qualities.
   did not hold for very small aspect ratios, and that, ID fact, the           Some early tailless aero planes, such as certain experimental
   induced drag of disc wings was less than the theory suggested.           types of Rene Arnoux, had rather stub wings a nd heavily
   In sP.ite of this, however, nobody seems to have he~ded the              reflexed (i.e., positively stable) aerofoil sections. A 19?9 design
   possibilities implied and the " ~attle of the Aspect Ratios" was         of G . Ab rial showed an aspect ratio of 2.88, with, however,
   decided in favour of slende r wings.                           .         substantial tip discs (which have the effect of increasing the
     To be fair, it must be pointed out that there was one senou~           aerodynamic aspect ratio) a nd wind-tunnel experiments indi­
                                                                 I
                                                                            cated a creditable performance (Fig. 13). Russian attempts,
                                                                            in particular the parabola type of Tscheranowsky, too, were
                                                                            experiments with aspect ratios of three and even less (Figs. 14
                                                                            a nd IS). Their resemblance in shape to the latest designs of
                                                                            super-sonic aeroplanes is remarkable.                   .
                                                                                                    A Modttn Pioneer
                                                                               Further intcre~t in the aerodynamics o f disc wings was
                                                                            displayed by research workers with th.e arrival of Juan de la
                                                                            Cicrv:i's Autogiro. This was indeed s<>mcthing like a circular
                                                                            wing, a nd performance estimates were based on the properties
                                                                            of such wings. Yet the question of stalling stability did not
                                                                            a rise, bccau~e of the rotor properties.
                                                                               The real pioneer of the disc wing was a very able American
                                                                            research engineer of the National Advisory Committee for
     Fig. 12.-Experimental Hayden glider, 1925. Span, 19.7 rt. :            Aeronautics (N.A.C.A.), who proved capable of following
     length, 13·85 rt.; wing area, 173 sq. rt. All-up_ weight,              independent lines of development. In about 1930 Charles
                     310 lb. No lateral control.                            H. Zimmermann subjected the properties of disc wings to

                                                               NND 927545

--- PAGE 41 ---
MARCH S, 1948                                                        281
                                                                                                         e                THE AEROPLANf

                                                                          wing , tructures as well as for the pos\lbility of housing every·
                                                                          thing w11hm a wing.
                                                                              Hence 1hc1e a re very real design reasons for the preference
                                                                          of disc wings, quite a pan from the ea~cd accommoda11on of
                                                                          short-span aeroplanes.
                                                                                               Some R ernurkable Results
                                                                              Zimmermann establ.shed that the optimum a~pcct rauo "'"~
                                                                          found bet,..een the values o f 0.75 and 1.5. l he,c value,
                                                                          include both ,quare and ctrcubr wmg ,hapes. For a g1Hn
                                                                          win g sccu on (Clark Y) the latter gave the h1gh~t hft coefficient.
                                                                           1.85 at 45 degrees incidence, compared "uh a value of t.:!4
                                                                          at 14 degree, mc1dencc for an aspect ratio o f six.
                                                                              Funhcrmore. an important result "'•'\ evidence that at ~,n
                                                                          a,pect ra110 of unity hquare or elhpllcal .... ,ng,), and :11 an
                                                                          a,pect rauo of 0.9 (" mg "11h faired ups), no tendcnc)' 111

                                                          ...   - --
                                                                /         autorotauon could be found. A circular " mg (:1,ix-ct raw,
                                                                          of 1.27) ind c.llcd the po\\1hili1y of ~1urnrntation (1.e., ,rinningl
                                                                          at incidence\ below that of maximum lif1. 1 he 1nm1biht)' of
                                                                          ,pinning before the actual ,tall is reached is. indeed, e,tra·
                                                                          ordinary. All these rcwh, r.:fer to te,t• "ith the ( lar~ ,
         Fig. _14.-A Russian • puabola' glider of 1924.                   aerofoil section.
                                                                              Less establi,hed "as the contenuon th:11 d1..c wing would
                                                                          11ive improved la11:ral and longuudmal ,1.1h1htv at low incidence,
extensive wind-tunnel investigation and the publbhed reports              1 hi, ..ecm, ,11II 10 be a moot point of the Flyin!l Saucer.
\till form the ba,is of prc~ent development. In places.                       In Fig. 16, Fig. 17. and Fig. 18 some charactcri,tic result, ,,f
 the re,ults confirm, qual1tat1vel)', the experiments made '.!O year~
before. But, as mentioned earlier, these experiments had been
praet1C111ly forgotten.
   Zimmermann' s target has been the development of a really
 fool-proof aeroplane for amateur pilots. It is no u<,c hiding                                                                         7
 the fact that in n.:arly all accidents in which blame is attributed
 to an .. error of /'udgment" on the part of the p1lo1, th.:
aeroplane is :ietual y at fault. The moq common causes arc
the consequences of inadvertent ~tailing.             Once this 1~
completely remedied, the overwhelming majority of accident
will become mere incidents or just fun, and instead of coroners
and hospitals. aircr.1ft manufacturer) and repair shop) will                      I!
have the benefit
   On such very sound lines (which seem to be generally                                                                        II
acknowled$ed , but still far too often ignored), Zimrrcrmann                                                                   I I
directed his main attention to the stall ing problem.                     :;.,
                                                                  He
;>roved that small variations in the aspect ratio made profound           't
                                                                          ...~
differences and that the shape of the wing tips also had a great                  0-,
influence.
   At the same time he confirmed that the induced drag of
circular or square wings is by no means as proh1b111ve as the
                                                                          ~.
simple theory of the " horseshoe " vo rtex line would indicate.
He also proved that it was simply the induced drag due to the
predominant influence of the marginal vortices which brou~ht
about the behaviour at high incidence~: the idea that the
                                                                                  ••
provision of oblique slots might help in this connection proved,
h owever, abortive.
   An advantaae which Z1mmermann' s research brought to
liaht was that disc wings gave less profile drag at small
                                                                                                                           CIA°', IIC,,O,.
incidences (high-speed flight). because of the reducti on of the                                                               -1....____..._
relative thickness of the aerofoil sections. 1 h is drag reduction                                                      .,,.     JO'       -:
has indeed become one of the rr.ain reasons for di.c wings
being adopted for aeroplanes capable of flying at ~reeds at                      Fl&, 16. -N .A.C.A. tests by C. H. Zimmermann which prove
which the compressibility of the air needs to be considered .                          the extraordinuy sull1ng qual1t1es of disc wines,
Fo r supersonic flight disc wings seem, at P.rcscnt, to be a
necessity. Alternatively, for a given aerofoil thickness ratio,
!he height avail_able f<?r st,:ucture _and stora1te (J?Ower plant_sl     Zimmem1ann·~ _wind-tunnel experiments of 1932 are given. It
1s greatest within a disc wmg; this ma.,es for light and sutr            1~ seen from F,,. 18 that the difference between the mc1deoce
                                                                         of ma,umum hft and the gliding angle at m:i1t1mum hft
                                                                         ("ma'< •a ma'<) rem:im'I fairly independent o f aspect ratt,,, and
                                                                         of the o rder of 9 to 13 degree,. 1 h1~ would me:in th.11
                                                                         the attitude of the . disc-type aeroplane, when flattening out,
                                                                         would not greatly d iffer from that of convcnuonal aeroplane,
                                                                         In particular, there "'ould be no need 10 provide h1g_h under·
                                                                         cama;ies for disc aeroplane, a .. their gliding path 1s steer
                                                                         Thi, 1s an important difference from "''"IJS w11h lead1ng-cd~~
                                                                         ,lots.
                                                                           . In P!'3Ctice, however: the landing of disc-wing aeroplane,
                                                                         ~•vcs rise to undercarriage problem,. As the induced dra~
                                                                         mcrcascs rapidly "ith the reduction of !tying ~recd, when the
                                                                         aeropla ne flattens o ut prior to touchina·do" n, the ihdtnti angle
                                                                         .iecpens abruptly. This 1s particularly true of ta1llc..s de"gn,.
                                                                         and the result •~. a strong tendency to pancake 10 the ground
                                                                         a, so~n as the p1lo_t fl:\ltcn, out. Thu~ to avoid the nccc\,il)
                                                                         of litt1!)2 _undercamal\cs able to sta nd the strain of abnormally
                                                                         high sink mg ~pecds, 1t has been found practical to land "Jtll
                                                                         powe r on.
                                                                              For a ta11le~s aeroplane " ith an aspect ratio of three,
                                                                         M. B. Morgan found that. without flaps, the trimmed l\liding
                                                                         angle at 160 m.p.h . was th ree degree,: it increased to 17 degree,
                                                                         at 126 m.p.h .. while the \tailing speed was I IS m.p.h. Thi,
                                                                         pronounced , teepcn ing of the g)idintt anttle makes a mer~er
                                       ,                                 hct""ce~. the aeroplane and the helicopter an attrac11ve
                                                                         propos111on .
    Fie, 15.-A ' puabola ' aircraft by B. I. Tschennowsky.                  . Another occulia_rity o f . !he di~ wing cstahlished b~
                                                                         Zimmermann wns us scns111v11y to the , hape of the wing•ur,,
                                                           NND 927545

--- PAGE 42 ---
'     THE AEROPLANE

    and _pseudo-circular and pseudo-square wings thus exhibit
    ~ignificam d.fferences... 1 his also applies to the ground eff.:ct,
    1.e., tbe tand.ng <juahues. 1 he prov1s.on 01 ob11que nozzle­
    shaped slots at the lips yielded no useful r.:sults. In any case,
    squo1re-cut tips Vvere found to be a disadvantage, w11h respect
                                                                                             282




                                                                                                     i
                                                                                                          c:,_                       •                    MARCH 5, 1948




    to drag, as well as to other qualities.                                                                                                                                  10
         Later N.A.C.A. research by F. E. Weick and Robert Saundefs
    referred to aspect ratios of the order of 3 1n conncct,on w11h
    slotted auxiliary Vevions flaps for the trim of tailless aeroplanes.
    This constituted the first investigation o f what has b.x:ome
    known to-day as the .. Delta Wing.'' i.e., the combination of
    sweep-back with low aspect ratio. Such shapes are of special
    interest for aeroplanes capable of flying through the trans-sonic
    region.                                                                  •                                                                                                    g
                                Pancakes Ii la Zimmermann                                                                                                                     10
                                                                                                                                                                                  :
                                                                                                     0
         The results of Zimmermann's research were so ~onvincing                                                                               Cl ARK I AEAO FOtl SECTION        ""'0<
    that a number of otherwise quite respectable designers were
    tempted into experimentation with disc-wing aeroplanes. In
    accordance with Zimmermann's views, all these designs were
     intended to be of the safety-first type of privately owned
                                                                                                                                                  (i-v-CA ZIMME~MANN,
                                                                                                                                                        ~l P No ()1)            --..
                                                                                                                                                                                  :;


     aircraft. This distinguishes the early phase from the more
     recent interest in Flying Saucers.
         In '1934 Farman was stimulated into experimenting with a
     wing with an aspect ratio of only 1.9. 1 his was seen in his                                              o ' - - - - ~ - - - L - - - J L _ ._ _..L._ _...L._......:~,
     F-1020 monoplane which otherwise had a long fuselage with
     a conventional tail. It was said to have proved very stable
     in flight. but was noc further heard of.                           An experimental
                                                                                                                                                           ASPEC T AATIO   .,
                                                                                                                                                                          .,
     parasol monoplane with a completely circular win$, a camber                                          18. -Furthcr results from Zimmermann's tesu shown here
     flap in the trailing edge and severely skewed ailerons Wl?.$
                                                                                                          also indicate the advantages to be gained from disc wings.
     tested in the U.S.A. (in 1934), with indifferent results. It was
    shown in flight in news reels.
         At about the same time Raoul J. Hoffmann. of St. Peters·                                    seem to. contradict the experience referred to above and it
     burgh, Florida, an eminent aeronautical engineer of Austrian                                    w~s aunbuted. to. a ground effect arising from the rak~ of the
     origin (known as the first to prove-in 1913-that the r:itio                                     wing-tips. It 1s indeed rea:.onable to e)(pcct that the presence
    C '/C 9 governs optimum climb and glide with minimum of t_he ground would affect the formation of the marginal
        L           D
     sinking speed, took up development of the disc-wing aeroplane.                                  vort1c~s to an ex\ent which may markedly influence the
         H offmann's Flying Saucer was a tailless aircraft with an                                   beh~v1our of disc wings during take-off and landing. Hoffmann
     aspect ratio of slightly over 2. The fi rst type was an ultra·                                  proJected a ousher and a twin-engined version but these types
     li$ht single-seater with 36 b.h.p. Later a side-by-side two-seater                              did not materialize.                                         •
     with an 85 b.h.p. Cirrus engine was constructed and flew well;                                      A further development was the Arup monoplane of
     the wing tips served as ailerons and the elevators formed part                                  R: J. Hoffmann and C._L: Snyder at South Bend, Indiana. The
     of the trailing edre. The aerofoil sectir,ns employed were                                      w!ng _shape ~as v~ry s1m1lar. I~ resembled a semi-circle flying
     N.A.C.A. M.6 basically. with N.A.C.A. M.1 at the tips. Both                                     w11h 11s straight side a_s the_leading edge; to this wing, ailerons
     are sections designed by. M. M. Munk. The former is a reflexed­                                 were added as special ups. 1 he aspect ratio practically
    camber section with a practically stationarY, centre of pressure; corres~onded to. that of the previous Hoffmann types. Again,
     the latter is symmetrical                                                                       aerofoils wtth little centre-of-pressure travel were used.
         The central structure of the wing, the fuselage and the fin                                     1 he latest type ~ad it~ _tailplane and elevator separately
     was of welded-steel tube; the wing had three spars.                                     This    locate~ over the wing tr:11lmg edge (similar to the .. Elytro·
      little two-seater }"as stated to fly well and to exhibit ve_ry go(!d                           plane o f De Rouge!). It seems that the longitudinal control
     stability.             It seems, however. that the controllab1hty, m                            at certain incidences was not satisfactory. 1 he ailerons which
      particular directionally, was not satisf~ctory. 1 he visi(?n fr(?m                             formed part of the wing shape and reduced the aspecl ratio
      the cockpit must have been very restncted--a moot point wllh • to a value ~f I:15 had a triangular shape and were greatly
      all these designs. A speed range from 28 m.p.h. to 13S m.p.h.                                  s_kewed (taking_ into account the obliqui: flow over the wing
      was claimed. The empty weight was given as 900 lb •• and the                                   tips). The engine was a 70 b.h.p. Le Blond radial; a tricycle
      wing loading was 5.5 lb. / sq. ft.                                                             undercarriage was fitted.
           One remarkable characteristic observed during the flying
      tests of Hotrmann's aircraft was that, when comin(! in to land.                                     With the oilot alone, a gliding speed of 23.S m.p.h. was
      the approach was steep: yet prior to the fl lltening out and                                    r~o_rded (lhe wing loading was about 3.3 lb./sq. ft.) and a
       just before touching down, the glide flattened. 1 his would                                   gliding angle of 21 degrees was mea~ured, with a sinking speed
                                                                                                     of 12.3 ft. ocr si:cond. wh.ch ~an be accommopated by a sturdy
                                                                                                     undercarriage witho ut nattening out of the glide. 1 he maxi·
         C                                                                                            mum speed was 86 m.p.h .. and the take-off was stated to require
         r
            l MAJ(
                   -                   C   jc
                                         l MA.( 0 MIN                                                S secs. in zero wind.
              0 MIN                                                                                      Several more Arup types seem to have been constructed
                      ,001----.U---4---1-- -4-- --4-- - - - + - - -~                                 an_d _flown during 1935. 1 h~ flying qualities were pr.iised­
                                                                                                      ghding angle~ or I : 2.6 bemg quoted- and the published
                                                                                                      performance figures sounded extremely good. Yet, for reasons
                                                                                                      never disclosed, the production stage was not reached and the
                                                     CI..Akl( T AUl,OfOtL SfCTl()N                    development ceased abruplly. It is worth noting that Charles
                                                             C,.ACA • IP No u,)
                                                                                                      Zimmermann himself has taken no part in this development,
                ..,z
                                                                                  ;•f                 b1;11 he was an interested spectator at demonstration flights
                                                                                      .,,.            wnh an Arup monoplane at Langley Field.
          ~ ~ 60                                                                         J
          ::,., l5
                                                                                     " ...      "•r                              An Italian "Tortelllno "
       !i        z
                      "'                                                              fl"
                                                                                         J
                                                                                           "<It
                                                                                           ~ •>
                                                                                                          At the time .of the Arup development (1934). F. Piana
                                                                                                      Canova. an Italian, began to embark on a development for a
                                                                                                      tajlless aeroplane with a low aspect ratio. In May, 1935, he
         "It• 0  It
                                                                                           ti     ~
                                                                                      11f 2           secured patents for a rhomboidal wing, one diagonal of which
                       10
                                                                                            c!, " z   coincided with the direction of flight. 1 he ailerons were to
                ~                                                                                 6
                                                                                     t            i;  be located at the lateral apices. elevator and rudder at the
                                                                                                      rear apex. while the airscrew was in front of the leading apex.
                                                                                                      Another patent related to bi-convex aerofoils with ducts and
                         o·                               •                    AA
                                                                ASP(C f U flO ( •' 1J
                                                                                                      control valve~ for the pilot, enabling the latter to neutralize
                                                                                                      the negative oressure on the forward ventral surface when at
                                                                                                      negative incidences. The latter patent was, apparently, never
                Fig. 117.-These resulu from Zlmmermann's wind-tunnel                                  submitted to flight experiments.
               tests on disc; wings (1932) clearly show the character!stits
                                                                                                                                       (To ~ confin~d.)
                                  of low aspect ratio aerofoils.                       NND 927545

--- PAGE 43 ---
MARCH 19, 1948
                                                         ,                      337                                                                  THE AEROPLANE


                 The Biology of the Flying Saucer- III
                                                   By A. R. Wcyl, A.F.R.Ac.S.
                   Previous articles In this series appeared In " The Aeroplane" for February 13 and Morch 5


WofI of0five-·11h1,UNC:anovo1
"'!Cnl
                          l· L I F-••n S w.:rc made in I unn and at Rnme
                               project\ {de-.cnbcd m the prcvtom tn\1,11-
                      ar1de). It " in1erc,11ng 10 note that 1he Canov.1
 d1-.c-wmg lype, d id not mal.e u,e of rellc'<ed~ambcr aerofoil,.
S1abili1y ,ind mm could . 1hercforc. be -..:cured only by an
 upward, dcllec1iu11 of enlarged eleva1or,.
    F.arly in 1935. :in ·open ghdl!r of 1he " Zoegling" t} pc wo1~
 con,1ructed by a ,~ ilan firm and M. A. Garbell made fairly
 ~ucce,,ful l11ghh w11h 11. He reported that the longitudinal
stability (w11h the enlarged eleva1or) wa~ good and 1hat
 par.i.chute-lil.e landing, could be performed.       rhc lateral
stability ch.i.racteri\lic. however, proved deficient. ~ince a
•• Dutch-roll " motion was experienced: turn, were of quc,tion·
able steadine,,. In this rc,pcct, in~uffidcnt damping 1n foll
and yaw a_re mentionr.d. Wi1h winch-launching, thi~ glider
 reached altitude~ of 600 fl.
    On 1he ba"' of thi, dc,ign, a ligh1 aeroplane wa\ developed
and the Italian Government financed the conMruction of two
 l~~gcr e,-perimental aeroplane~. includmg one with 130 b.h.p.
Gip,y engine. A faial accident de~ribcd as "not necessarily
 retlccti~f? on 1he 1echnical _merit5 of the design," cau,cd the                          Fig. 19.-An American "Flying Flapjack" w ith two engines.
authorities to change 1hc1r minds and 10 terminate this
development.                                                 1                                        It crashed while under test (1938).
                     A Return to Child ish Things
    Aeroplane, with a long, deep tail affi'<Cd to a smalhpan                         A third de,ign tin 1938) 1hc "Flcchair" \tngle-,cat fil!hlcr
 wing form a development of lhe low•tl'pect wing in another                       rroiect. therefore. incorporalcd two co.1xial coun1cr•rot.11mg
direclion. Although the overall a~pect ratio is low wi1h such                     ~tf'>Crcws driven by two 100 b.h.p. engines mounted in 1andem
a n arr.rngemcnt. the wing system i, not tha1 of a di-.c. It is                   m the long fuselage. 1 he pilot's cockpit was located at the
 more akin to primitive kites or. belier, to the paper dart of                    root of lhe fin, and a single·lrack undercarriage w.is adopted.
 our school day~ which. a, we may be able to remember wi1h                        1 here were. however, far too m.iny untried feature in th"
some mental effort, exhibited quite remarkable nying quali1ie,                    unusual design 10 make ii a ~rious proposi1ion. Nothing
and made better use <>four schoolbooh than we ever expt-ctcd.                     more has been heard of Payen's cffoA~.
    A rcpresent:11ive of 1his aboriginal 1ype is shown in Fig. 19.                   l he ll)Odern ph:ll!e of .1he Flying Saucer aeroplane i,
It crashed during the first tests (which would not seem very                      charactcn1ed by two d1,ttncl development~.          One is the
surprising in view of the; arrangement of engine, and air;crew,).                 hclicop1er-aeroplane, 1he other is the tranb•\onic or buper,on1c
    Ano1her Je,s eccentric arrangement was the French Payen                       aeroplane.      Hoth have bccome:-unforiunately--cs<;entially
single-seat racer of 1935. This was a daring experimental                         military dcvcl_opment~; the proJ_!re~~ is ~cnce bhroudcd in the
type with a 400 b.h.p. radia l engine. A n improved type, this                    u~ua I pretcnuou~ \ecrccy Iwhich implies that the potential
time more reasonable--a 70 b.h.p. light aeroplane- was                            enemy knows everything) v. hile the work is gravely hampered
constructed in 1936. To a very small. conventionally tapered                      by elabora1c securi1y precautions.
wing, a large triangu lar tail was fitted: the wing alone had                        The helicopter-aeroplane is not a novel idea. Many }Cars
d ihed ral. and the overall aspect ra1io was about 1.76. No                       ago, for in,iance, Nicola T e~la (famous for his elccirical
flights have bc.:n reported of one of these Payen aeroplanes.                     experiment~ wi1h high-frequency phenomena) bccured a pa1en1
but take-off attempts with the ~econd type seem to have                           for a taille,~ aeroplane equipped with a large lifting air~rcw
sugges1cd that with 1he small span the 1orque reaction of the                     pcrmi11ing a vertical ascent.
air,;crcw ca nnot be adequa1ely dealt with.                                          In 192 1 Claud Dornier ~ecured a pa1ent for a eonvcnlmnal

                                                                 1/lO C
                                                                                                           -          - ·-~
1110 C


f
         L
                                                                lL:             .__ ._                                          GI
                                                                                                                              c• t      •
                                                                                                                                                     Fig. 20.-Llft and
                                                                                                                                                     drag of wings of
                                                                                                                                                     different aspect

                                                                                                                 . :~
      120


                                                                '--- 100
                                                                         I                                      ,_
                                                                                                                                            0        ratio. (Left) W ind-
                                                                                                                                                     tunnel results
                                                                                                                                                     obtained
                                                                                                                                                     Goettingen , in
                                                                                                                                                                      at
                                                                                                                                                                            \


                                                                                                         ~j                                          1920; Goettingen
                                                                ~~
                                                                  -        80
                                                                                          n        ...                                               389 aerofoil with
                                                                                                                                                     10 per cent. t hick-
 ~ eo t--t--;illt":!'-~ -+7"lr--+--+..-t---c¥~--+~                                                 19"                   ASPECT RATIO                ness and square
                                                                                                  0
                                                                                                  .»
                                                                  ...                     1                               0     1 SQUARE v, ING      wing tips. (Right)
                                                                  ~


  "                                                                                                                                                  A reduction of the
                                                                ...a:; ~60                                                +     2
                                                                                                                                                     r esults to an
                                                                   ...~               ~(                                  A     3
                                                                                                                                                     aspect ratio of
                                                                  w
                                                                  0
                                                                ._u ,o
                                                                                      (t
                                                                                      h                                   • '
                                                                                                                          0     5
                                                                                                                                                     f i v e.     by t he
                                                                                                                                                     Prandtl Aerofoil

                                                                                1·
                                                                  t                                                                                  Theory of t h e
                                                                  :::;                                                    4l    6                    Ind uced d ra g ,
                                                                                                                          ()    7                    s h o w s t hat a
                                                                ~
                                                                           w                                                                         s quar e aerofoil
                                                                                .t                                                                   (aspect ratio of


                                                               -
                                                                                                                                     - i--c          one) does not
         oQ-"11~t---t--t--:,~o- r-+ ---l- +-~ 20- +--+--I
                                               I
                                                                         I- 0    i€
                                                                                  I
                                                                                                                    10
                                                                                                                                                ID   follow the theory.
                                                                                                                                                     Its induced drag is
                                  ORAG C0EfFICIENT    100)                                                                                  20       less than pre­
                                                                                                                     I                          I
                                                                                      ~       I                     DRAG COEFFICIENT    < 100)       dicted by t he
                                                                '--        20                                                                        "h orse-s h o e
                                                                                                         0. :
                                                                                                                                                     vortex " assump-
                                                                                                                I                                             t ion.




                                                                          NND 927545

--- PAGE 44 ---
THE AEROPLANE                                                                              . 338                                                                                                  MARCH 19, 1948

•               100 C

                 t
                         L
                                                 l        ...l'
                                                                                                          I
                                                                                                          100 Cl

                                                                                                              t 1,10
                                                                                                                    I                                                                                   Fig. 21 . - LI ft
                                                                                                                                                                                                        curves of aerofoils


                 ~
                        1IO



                                            i\ ~ ~
                                                     AR 1


                                                   --;?  :a-:
                                                        ,_,... /
                                                                   ~
                                                                       LA>-

                                                                   L,CI"
                                                                                  ~
                                                                                  L-/
                                                                                         f
                                                                                                              -l                                             -
                                                                                                                                                                        ~· --
                                                                                                                                                                  . o,."'
                                                                                                                                                                              O+
                                                                                                                                                                                     ..
                                                                                                                                                                                          C
                                                                                                                                                                                                        of different aspect
                                                                                                                                                                                                        ratios. (Left)
                                                                                                                                                                                                        Wind -tunnel
                                                                                                                                                                                                        results obtained,

                                                   ~Vv
                        100                                                                                   ~- 100
                                                                   V                                                                                                                                    in 1920, at Goet•
                 ...-
                                             I
                                                                                                                                                         o"'f3.
                                                                                                                                                     I                                                  tlngcn, w ith




                              ,v
                                          AR~
                 :z                                                                                                                                                                                     Goettlngen 389
                                                                                                              ~ eo
                                                                                                                                                  IA .

                 ~
                        80
                                                                                                                                                                                                        aero fo i l and
                                          ~~
                                                                              V
                                                                                                                                            t
                                                                                                                                                                        ASPIC.T RATIO

                 ~                                 ~" Lu                                                       ~                                                        a     1    Aou,hf               square t ips. The
                 V
                         00
                                   ,.I.
                                                               ,, '                                           0V        00                                              +     ?      WING
                                                                                                                                                                                     ,__,__             absence of stall at
                 t:                                            't. .                                                                                                    .0.   J                         normal Incidence
                 ::;
                                          v v l,o' /                                                          t:
                                                                                                              ::;
                                                                                                                                       I+                               • •                             Is In evidence, for

                        '°
                              J
                        ~ -l.,o'
                                  1,,1" fif (r
                                                                                                                     ro
                                                                                                                        t'°I
                                                                                                                                       b
                                                                                                                                                                        .. ,· -
                                                                                                                                                                        .o    I
                                                                                                                                                                              ~
                                                                                                                                                                                              ,__
                                                                                                                                                                                                        aspect ratios up
                                                                                                                                                                                                        to a value of two.
                                                                                                                                                                                                        (Right) Reducing

                                                                                                          ,,.                                                           ()                              the values. by the




     ., .
                                                                                                                                                                                                        Prandtl theory.to
              .#J ~                                                1 -► (l
                                                                                        o·
                                                                                                     cf                                                                       --<
                                                                                                                                                                                                        an aspect ratio of
                                                                                                                                                                                                        five, shows t hat
                                                                                                                                                                                                        wings of very
                                                      10   °                       10                                                                  10 •                10                           small aspect rat io
                                                       I                                       0 '                                                      I
                                           •NGt[   or INCll)[NC( ( O!GRCES i                                                                AN(;l[ Of tNCIO(N(( t OIGRH\ I                              do not follow the
                         10                                                              ...                             IO                                                                             theory in respect
                                                                                                                                                                                                        of the induced­
                                                                                        ~                                                                                                               Incidence correc•
                                                                                                                                                                                                                tlon.

    aeroplane with take·off as helicopter {Brit. Pat. Spec.                                               control organs directly in the slipstream of tht: paddle-like
    No.161,948). Earlier still (in 1916), the German, F. Bendemann,                                       airscrew rotor... T he twin rudders, too. are in the slipslfeam.
    a noted fesearcb worker on a1rscrews, conducted a secret                                              Unlike the V-173 type, the XF-SU· l has an all-moving tail
    development o f an aeroplane with a large tilting airscrew                                            surface and the undercarriage is retractable.
    capable of rising and descending as a helicopter.             The                                        This interesting hybrid has a modern metal structure. Two
    development of this air observation post was later discon•                                            Pratt and Whilney R-2000-2 engines Qf 1,350 b.h.p. each (at
    tinued in view ot the Austrian helicopter experiments by                                              2,700 r.p.m.) are mounted within the wing, entirely buried and
    Th. v. Karman and Petroczy.                                                                           cooled by forced draught. Water injection for temporarily
       From his early experiments with lifting airscrews,                                                 boosting the oower is one of the engine features.
    F. Bendemann found that hoverihg without forward movement                                                A special oroblem was the design of a transmission ~ear
    could be achieved- when the power loading of the aircraft was                                         which a llows both rotors to be driven from either of the eogmes
    less than a bout 9 11,.. / b.b-.p. With fighter aeroplanes, such                                      - this is a necessity in case of an engine failure. The four·
    low power loadings were already then being approached1 and                                            bladed rotors are contra-rotating so that there is no residual
    operat ional experience bad indeed shown that certain single·                                         torque and are ,eared down to about one-fifth of the engine
    sealers could. under favourable conditions, be held in attitudes                                      speed, hence their substanlial diameter. The wing loading is
    a pproaching that of hov.ering (later the Fokker D.Vll biplane,                                       rather high. reaching the order of 40 lb./sq. ft.
    with a large airscrew, became renowned for this trick 10 air
    combat on the Western Front). Attempts to revive the project
    ~ta la ter date failed. and with the suicide of its promoter (who                                                             The Real Flying Saucer ?
    had gone into the Civil Service), all interest lo the development                                            Since this experimental t ype was produced, further progress
    ceased.                             •                                                                     has been made in the development. IL seems that axial-flow
       Charles W. Zimmermann, mentioned earlier as stimulator of                                              gas turbines have been installed, and it is quite possible that
    the disc wing, approached the conception of the helicopter                                                a combined oropulsion with thermal jet and airscrew rotor
    Aeroplane on the basis of his results with low aspect ratio                                               is alt:eadv under test. Wilh this, for slow flight (take-off,
    wings.     He secured basic patents and constructed during                                                climb and landing) the rotors a re driven by the gas turbines,
     1934·35, in the cellar of his home, a man-carrying aircraft of                                           while at high speed the rotors are declutched a nd feathered
    bis design. This had a wing of only 7-ft. span, with two                                                  and pure jet propulsion is used. This would, incidentally,
    airscrews driven by two 25 b.h.p. engines. Due to persistent
    engine trouble, no flights were made; the Little aircraft showed,
    however. all the C$SCOtial features of the present types.
       In 1937 he granted a licence for his patents to the Chance•                                                                                       (
    Vo ught Aircraft Division of the Unik:d Aircraft Corporation                                                               ~01! 1---1---1------.1---1----1----1
    in Strntfort, Connecticut, and /'oined this firm for the further
    development of his ideas.          t is possible that the public
    conception of the mysterious "Flying Saucers" has origmated
    from this develo,,ment.



                                                                                                                              -
       Zimmermann's intention may have been the development o f
    a safety-first aeroplaoe for the private owner. The U.S. Navy,                                                   ;
    however, took an interest in the possibilities of the helicopter•                                                0
    aeroplane, and the work done at present is purely for military                                                   ~
    purposes. In 1942 a low-powered piloted scale model type                                                         ,.
    V-173 was constructed. This wooden aircraft made many                                                            <
    flights and proved that the ideas underlying the design were                                                     i
    practical.                                                                                                       Q
       The principle is that, at h igh speed and when cruising, the                                                  :::                   ...-                                    NACA 14 SEC11C)N:~
    aircraft shall fty as an aeroplane, while for slow speed and                                                     iSV
                                                                                                                     ..,
    hovering it flies as a helicopter. Hence the airscrews are at                                                              0-00,
                                                                                                                                                                                          ._N• '1·1 , 10'
    the same time rotors and must have a rarher large diameter.                                                      ~
                                                                                                                    0
    With the V-173 the problem of the prone position for the pilot
                                                                                                                    i ~
                                                                                                                                                                                          0.~L T!HI
    was studied. and there is reason to believe that the latest types
    have adopted this feature.
       A further step towards the realization of a naval gun-spotter                                                             ,.                                                           ...
                                                                                                                                                                                               I



                                                                                                                                                  -
    and a fia),ter for use from aircraft carriers bas been the Chance·                                                           ~                                                                                    T{C
    Vouaht XF5U·l single-seater (1946), for which a speed range
                                                                                                                                   ~
    from 40 m.p.h. landing speed to over 425 m.p.h. has been                                                                                                      ~01         0-ll              0-16        ~IO   0 •1'
    claimed; in general, it follows the V-173 model. (See p. 185,                                                                                                        AU,0r0tL TMICKNESS A.ATIO
    February 13.)
       The aspect ratio of the wing is lesa than unity. Strictly                                                    Fie. 22.-lncrease of profile drq with section thickness, at
    speaking, however, it is not a genuine tailless aeroplane because                                               :zero 11ft. The lfnporunce of the tip shape Is obvious.
    of the attachment of a trimmmg elevator to both sides ot the                                                    The data refer to an aspect ratio of flve (From D.V.L. wind-
    wina. The reason for such excrescences is the need to locate                                                                  tunnel tesu at low turbulence).


                                                                                             NND 927545

--- PAGE 45 ---
0·3
       .,   ...
            ~ ARCH 19, 1948


       r - - - - - - - -- - - - - - - - - - - - --i~
                                                                                          339                                                        THE AEROPLANE

                                                                                                  M. B. Morgan has recently communicated the following
                                                                                                values for the limit of stability at the stall from this araph:-
<=o,                                                                                            Upper llmic of th• Ansl• of Swetp,back (r•lerred
   0
                                                                                                to th• l chord) beyond which Hll••tall can be         A,poc, Ratio 11.•qulr•d
                                                                                                                   expected

                                                                                                                    Ocareu
                                                                                                                       6S                                        1
                                                                                                                       S4                                        2
                                                                                                                       46                                        3
                                                                                                                       38
                                                                                                                       2S
                                                                                                                       14                                        '
                                                                                                                                                                 6
                                                                                                                                                                 8
                                                                                                                        s                                       ••
                                                                                                          It is thus advisable to combine sweep-back with low-aspect
                                                                                                      ratio w!1en s~fc stallin_g is required.
                                                                                                        . Consaderataon, of high speed lead to a ,imilar combination.
                                                                                                      since both feature~ tend to delay the shock stall. We have.
                                                                         o-a 04 1·0                   as ~ res!lll, the rare ca~ i;,f two quite d ifferent aspects of an
                                                                                                      enginee~ing_ problem pointing to an identical solution.
                                                                                                           1 he incv11able result has been the development of arrow­
             Fig. 23.-lncrease of xero lift profile drag with thickness ratio                         sh<;1ped:. more ?r less triangular, . disc wings, termed " Oelta­
             of symmetrical aerofoil sectldn. The saving In profile drag Is                           Wangs, _for lhgh~ at sp~eds which are trespassing into the
             one of the advantages of disc wings because of their thinner                             tr~ns•s?nlC velocity rtg1me. Another advantage of such
             aero~oll section. (Data from Gerber, Zurich Report No. 6).                               wings as that when the shock stall occurs. the backward shift of
                                                                                                      !he centre of pressure is less than with normal wings. The
                                                                                                      induced drag doe, not count quant itatively at tbeg high speeds
         explain the extr~ordinary ability of the reported •• Flying                                        Development of such abnormal aeroplane types began i~
         Saucers·• to be able to fly very fast and high, and also to hover,                           9e:many during the War_. following the progress accomplished

This text is truncated. The complete file is available at the official source.

View the official file

Congressional Context

No confirmed links between this file and the congressional record yet. Connections are added only when the source text supports them, never inferred.