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

Authority:
NND927545
•
•I
HEADQUARTERS
AIR KATERI BL COWAND
MClA/JCB/amb
Wright-Patterson Air Force Base
KCIA
2DjytAPH
0i948
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 Intelligence, 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 lity 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 purauit plane to tht
ePulk of six B-29 airpl.&nea.
,
NND 927545

2 3 APir 1948
over 10
9
•
..
AMC
Subject, Project "SIG!i"
e. »umber of objects per aighting,
Objects per sighting
l
2-6
6-10
Number of eightioga
77
21
8
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 iovited to the marked aimilarity 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
H. M. ticC~!1. J
l. Tabulation
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

/ •
CONFIDENTIAL -
Incident
No.
Date
1
g Jul 47
;
la
g Jnl 47
lb
e Jul 47
le
g Jul 47
ld
g Jul 47
le
g Jul 47
2
g Jnl 47
~
7 Jul 47
4
$ Jul 47
5
4 Jul 47
6
4 Jul 47
7
4 Jlll .47
~
4 Jul 47
9
4 Jul 47
10
4 Jul 47
ll
4 Jul 47
12
4 Jul 47
1~
4 Jul 47
14
4 Jul 47
15
4 Jul 47
l.6
4 Jul 47
17
2ll. Jun 47
l!S
not stated
20 Oot 47
20
19
20 Oct 47
Hour
0930
0930
0930
09tl9
1000
1000
1200
1010
1150
1305
1305
1305
1305
1305
2004
N<>•
Obser,ed
Location
Sighted
P'rom
Muroc ilT Field, M'uroc, Calif.
Muroc,Air Field, Muroc, Cali£.
Muroc Air li'ield, li&uroc, Cali.f.
Muroc .lir Field, lluroc, Calif.
lmroc Air Field, Muroc, Calif.
Uuroc A.Lr Field, itiuroc, Calif.
Muroc Air Field, Mu.roe, Call!.
Iifuroc Air Field, Vuroc, Calif.
Area 113, Rogers Dry Lake, Muroc
Air Field, Muroc, Calif.
~ortland, Oregon
1llli.lwaukee, Oregon
Portland, Oregon
Portland, Uregon
Portland, Oregon
undetermined wt atated
Roi se, Idaho
5
Air
2
Ground
2
Ground
2
Ground
2
Ground
3
Ground
3
Ground
1
Ground
1
Ground
l
Ground
5
Ground
3
Grotmd
1
Ground
3
Ground
not stated Seattle, Xashington
l
r.:.round
1305
Vancouver, Washington
20-30
Ground
1400
Portland, Oregon
4
Ground
16}0
Portland, Oregon
1
Ground
1700
Portland, Oregon
3
Ground
ll.00
Mount Jefferson near
4
Ground
Redmon, Oregon
1500
14t. Rainier, a.shington
9
11r
not stated Toronto, Canada
1
Ground
1320
Dayton, Ohio
2
Ground
1100
Xenia, Onio •
l
Ground
CONFIDENTIAL
NND 927545

31
CO~FIDENTIAL e
No.
Sighted
l~
1
2
l
l
l
l
10
1
l
l
1
l
1
1
1
1
1
1
1
1
l
,
~
l ,l ­
I.
~
\
\
\
I
Observed
From
not stated
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Oroum
Ground
Ground
Ground
llr
Ground
Ground
.
Ground
Ground
Ground
~
Ground
Ground
Boat
Incident
No.
Date
21
29 Jun 47
22
21 Jwi 47
23
30 Jun 47
24
12 J\111 47
25
4 Jul 47
26
10 Jul 47
~
10 Jul 47
2g
24 Jun 47
29
23 Jun 47
30
7 Jan 4!
30a
7 Jan 4g
30b
7 Jan 4a
30c
7 Jan 4g
1946
32
32
not stated
33c
33d
33e
331'
33g
34
35
7 Jan 41!
7 Jan~
7 Jan~
7 Jan 4g
7 Jan 4a
7 Jan 4g
7 Jan~
7 Jan~
13 Oct 47
12 Nov 41
dour
1645
about noon
1745
1&5
2345
not stated
~
not stated
not stated
Location
Des Moines, 1owa
Spokane, ·1ashingt,on
Boise, Idaho
Weiser, Idaho
Vfest Trenton, t~ . J.
Harmon Field, Newfoundland
Hamon Field, bewfoundland
Idaho
Bakersfield., Calif.
l~T Lockbourne AB, Co1umbus, Ohio
1925EST Lockbourne,!B, Columbus., Ohio
1915EST Lockbourne AB, Columbus, Ohio
1940
Lockbourne il, Columbus, Ohio
mid-December early a.m.
Northern Arizona
after dark Columbus, Ohio
133&.l'T,OO"'
Oocbnan Field, Ky. (south of)
l4000ST Godman Field, Ky.
1320CS'J.' · 0odman Field, Ky.
J..420 CST 2100 from Oodman Field, Ky.
J..430-1600
11!54-19()6
05}0
GQ'l.Jr a.m.
Gedman Field, Ky.
Godman Field, Ky.
Godman Field., Ky.
lladi.eomi-1.le, Ky.
l4 mi1es north of Dauphin,
J.lanitoba, Canada
ticonderoga at sea (40 miles
south of Cape dlanco, 20 miles
o£f shore)
CONFIDENTIAL
NND 927545

vu~FIDENTIAL
-
.
lo.
a...nect
DIOIDD'f
Is,
;w.
12111:.
r,ooat1cm
SMaatfd
rra
,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
18
Oro\lDd
43
29 Jun 47
1645
Clll"1on, Ion
28 Jun 47
1~,
Roekt1tld, W1■cou1n
7-10
Ground
"
7-10
Ql"0\1DC2
28 .Jun 47 Afternoon n11no11
-5
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
_,,,.,.•
1
Qrowu1
481>
7 Jan 48
1910&ST V11111ngton, Ohio
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>aJffi11e , ltntllolq
1
Qroimd
One at tb11 Orouad
50
10 Jan Ji8
2200
11lcSVood, In Jei-■r,
date, PNT­
1wa17 1 ..oh
27 Deo,, JUI
all at 2000 o1oloek.
'Sept lf
1215
on.ao, oneon
12-15
Ground
51
52
29 Jul 47
1450
1181111 ton 11eld, Cal1torn1a
2
Oroad
2
Ground
,,.
29 1111 •n Atter 1200 llllilton Jield, ca11tarn1a
53
28 Jan IJ7
1515
Lake Jllead, ore1on
5~
Air
1
Air
16 Jan IJ7
22:50
Jorth Sea (50 ail•• troa
54
tbe Dutch coa,t)
l
Orolll\d
BIJ'llCffl Pield, ltvtoundland
2:, Jul 47
o,45Z
55

-CQ~F~DENTIAL -
-
IAo1c1ent
?fe,
15a.
us.
Looat1on
lo.
simaa
Ob1enec!
D:99
56
6 Jul 47
2945
1-10
Gi-oan4
57
20 lul 47
0015Z
Abou-c! the BUl'aeo (at sea
one hr. troa 874ne7, Autft11a)
1
Boat
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 CltJ, 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.
55.
Ol'oun4
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,
Pwtlan4, 01-egon
6
Ground
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

80
85
90
95
100
coNriBcNTIAL
lno1dent
Jo.
°'8tl"Ytd
19,
em..
Looat1op
SUhtn
rrw
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
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 ) Gorm.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
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
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
5 Jan 46
lot 1tated Pretaraa&rl, F1nla1'ld
l
Ground

•
Incident
Observer' s
No .
1
la
lb
le
l d
le
2
3
4
5
6
7
9
Occupation
1st Lt, UJAF
:,/::,gt, 0::i,v'
Uninown
s/sgt, USAF
Pfc, USAF
~fot stated
:Uaj, USAF
liajor, USAF
Capt, USAF
Patr olman, ?ortland
Police Dept.
Sgt, Oregon Police
Patr olman, Por tland
Police Dept., former
Air Force pilot
Patrolman, Portland
Police Dept. Pri­
vate pilot
Patrolman, Portland
Police Dept .
?ri­
vate pilot
Capt., Harbot pilot
Jo1aneuvers
1lone - horizontal fl1gnt
1"ot stated
t-:et stated
Not stated
Flying in tight circle
Horizontal anrl tipht circles
Descended from an intennediate
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.
Oscillating in a downward twirl­
ing movement
Falling at three times the rate
of a parachute
Dippi nP, up and down in oscillat-­
ing motion
Following each otner
Not stated
Str aight line formation; last
disc fluttered very rapidly in
side-way arc
Strai~ht line fonnation; last
disc fluttered very rapidly in
side-way- are
Discs wo'.lld oscillat e and SOl11131-'
times a full disc would be vis~
ibl e, then a half-moon shape,
t hen nothing at all
Heatner
IiOt stated
.,ot stated
l1ot stated
~!ot stated
!fot stat'3d
!lot stated
Not stated
Not stated
?!ot stated
Not stated
Clear with little
or no cloud forma­
tion
Clear with little
or no cloud forma­
tion
Clear with little
or no cloud for.na­
tion
Clear with little
or no cloud forma­
tion
Not stated
CUiqfiDE~~TIAL
NND 927545

10
15
20
25
30
•
Incident
ObaerTer' s
•oo
Ocoupad.on
Ka.neunra
Weather
Capt, United Airlines Straight-away horizontal flight
lot stated
ll
12
lS
14
16
17
18
19
21
22
23
24
26
27
28
29
30a
Coast Guard
Deputy Sheriff
!lot stated
Sot ste.ted
Jot stated
Mot stated
Private pilot
llot stated
Farmer
lot stated
lot stated
Wot stated
!lot stated
lot stated
Not stated
llecba.nic
TWA Representative
Lt Governor
ffest Coe.st Pilot.
7000 hrs.
Ca.pt. USAF. Asst
Operations Officer
VHF/DJ' Operator
Horizontal flight
Mot stated
Not stated
FUpping around
Not stated
Hot stated
Straight horizontal flight
Horizontal flight
Straight course - were flying
about a city block apart. one
behind the other
Straight course
Single file
Flashing
Horizontal flight
Shooting up and down
Hori&ontal flight
lot atated
llot stated
lot stated
Bot stated
Climbing and descending ver­
tioally
Hovering, made three 360
0
turns around one place. Moved
to another position and circled
more.
Turns required 30-40 seo.
Diaaeter estimated at 2 miles.
Kot stated
Not stated
Bot stated
Mot stated
Iot stated
Mot stated
Clear as crystal
Clear
Cloudless and
sunny
lot stated
Rot stated
Bot stated
•ot stated
Clear
Bright moonlight
Not stated
Clear
Kot stated
lot stated
Solid overcast
Overcast. 1000 ft.

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

(;J~iadJENTIAL
41
e
Ine14ent
lg,
1'1
Obaenv'•
QoogtS,on
Colonel. USU
•entuur•
. 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
np'idl7
Clear nth onr•
eut 1Jl S/1.
48d
49
lot stated
..
lot stated
laoendlng' and deaeendine
lone
lot lbttd
50
En.1.ttlng deatan.er
Approaohil!a llhON traa Ooean then
Pile and tall 1lovly.
lot stated
51
Jot 1tated
lot stated
lot 1tawd
52
Capt, USU, ASS'!.
Bon.aonal lett to ri&ht, ri&ht to
Opentiona ottieu
1•tt lib• cuard 1n an a1Pplane
~
inawuotor Pilot fOl'Mtian.
CltlP
52•
lit Lt. 1n Air
Il•••ne• t01:1Mr
B-29 Pilot
SSll1lar to a ti&hter aiNNtta
aueu.•r• llben ue~
heaT1.eP 1h1p1.
lot stated
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

-
Incident
Ol>aeryer's
110.
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
and deecendtng.
Scattered aull
olouda,
64
Executive Direct­
Hor11onal
OnNalt
or ot Housing
Authority.
65
P1lot
lfot stated
Not 1tated
66
Lt. Col, QSC
Sc1ent1t1c
Horizonal Pl1.g?\t
lfot 1tated
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
(Conatellat1on
type ail"cNft)
Not stated
5/l.O acattered
cuaulus vith
tops at 10000,
Y111b111ty 10
a11H.
74
Prospector
Standi.nc on edge and banking
1n the clouda.
Mot 1tated
75
Trout Parm Oper.
Rode up and dovn oyer the hills
and hollow ot the canyon tloor.
Mot stated
County COlllliaaioner Hot stated
Rot stated
It
NND 927545
76

In.ctdent
Ko,
77
78
79
80
81
82
83
~
85
86
87
88
89
90
91
92
95
96
97
98
99
100
Ob ■erTer'•
Qo9upgt109
Astronomer
Lt, USI (P80 Pilot
Weather r-,o7tff
Lt. Col. USAP
C1T11 Service
bplo,ee
P1eld Bngtn,er
Pilot
Sign Painter
Pl'1Tate Pilot
Hot 1tated
U. S. Army
Not stated
Major, USAF
Administrative Asst,
Rocket Sonde Section
Captain
Railroad Employees
Capt, USAP
L~ Col, Hq, EPlf
C-47 orew
Bot stated
Airplane crew
Immigration Service
Not stated
lfot stated
Manemrp
Not stated
lot 1t1ted
Rot 1t1ted
Jot ltated
A1oendtng slowly
Bot stated
Slow roll or barrel
Cl1Jlb1ng
lot stated
'l'm"ned a corner and seemed
to roll.
Descended slowly and then
dropped in a spiral motion,
Not stated
dot stated
Not at~ted
Traveling in zig-zag course
Climbing, diving and reversal
of direction whioh happened
enry few aeoonds.
Shooting toward, the eaat at
45° angle
Descending vertically - aeaned
to slow down on nearing the
earth
Not sta.ted
Bot stated
Not stated
Appeared to be spinning in
its descent
Bot atated
?lot stated
I L
NND 927545
J!eather
lot stated
lot ■ tated
Clear
Scattered clouds
Y111b111t7 10-12 ailea.
lot stated
S<ae clouds
Clear...cattered cloud•
lot stated
Clear
~ot stated
Not stated
Clear
Clear
Cle ar alld 1unny
Not stated
•ot 1tated
Not stated
Not stated
tiot &tnted
lot stated
lot stated
Not ata.ted

•
Incident
llo.
l
la
lb
lo
ld
le
2
s
4
5
6
7
8
Sa
9
10
Color
Silnr,­
S11Tery
Retleoted the •un' •
raya
Silvery
Ahai.num colored
1urface
Yellowiab-llfhite
lihi'te aluminum
lot 1tated
1'h1tiah-brown
J.lumima
White
1'hite
Like shiny ohro­
aium hub cap
.bot 1tated
Shape
Size
Not stated
Not stated
Saucer shaped
lot stated
Diac
llot stated
Diec
•ot stated
Thin metallic ob­
jeot, unconventi on
ah11pe
al
Purauit eh1p
Spherical
5 - 10 t't, dtaaeter
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
Round
.Not 1tated
Diac
Jllot atated
Di1e
Mot determined
Dile
Out ol light be­
fore det&iled ob­
Hrfttion •d•
Diec
Out of 11 ght be­
ror• detailed ob­
aen-at1on made
Di,o
Mot 1tated
Thin a.nd a.ooth
Not stated
on bottoa, rough
appea.rinc on top
NND 927545
Sound
Mot atated
■om
ltot atated
None
Mot stated
lot 1tated
.llom
Jllom
lone
!tone
Mone
!lot stated
Jot etated

II~· ,DENTIAL
Inoident
llo.
11
12
13
lt
15
16
17
18
19
20
21
22
24
25
25
26
27
28
29
50
Color
ffbi t e
mot atated
Resembled •tallic
Lin a new di••
Sil•er
Not stated
ltirror brit ht
Jellow
Reflected the 1un
brilliantly
Silnr
Dirty 1'hite
Shiny d l nry
Bri ght and sil•ery
Gli&tened in av.n
Luminous
lot 1tated
Silvery
'
Not etated
!lot stated
White (.light)
Shape
Saucer
Like tlock ot
geese
llot 1tated
Like a nn dime
lilot atated
Approximately
circular. no tail
Like ci ga.ra ­
11uch longer than
wide
Round
Betwe.n circle
nnd on.l - in­
••rt•d aa.ucer
Slim body
Ral t-circle
Too far away to
dotenune ahe.pe
Plying saucer ­
DO tai l
lilot etated
Citoular in shape
like a wagon wheel
·eomet-11ke
Almo1t round
dot stated
NND 927545
She
Jlot stated
•ot stated
lot 1tated
Like .. run, di•
lot atated
Not stated
Diameter equal to
di atan ce between
outboard enginea
of DC 4:
llot s t ated
Jlot atated
About 12 inches in
diameter
175-250 t't. dia:aeter
12 ft. t hiok
Quite large
Not atated
Too far away to
detenain. ahape
lot atated
Jiot sta'ted
Same apan •• C-54
at 10. 000 rt.
Not stated
lot stated
lot atated
Sound
~t stated
Low hmmdng
aound
l ot atated
lot etated
llot stated
lfot auted
lot atated
Not stated
Mom
Mone
Like electric
motor or dy­
nmo
Not stat ed
lone
lot atated
lot atated
Wot stated
lot stated
!lone

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
on top and taper­
ing orr toward
bottom
'
Rnonnou•
30c
White lligbt)
RoWlld
Comparable 'to
way light
run-
Bone
31
White
Not stated
lot stated
ltone
52
Amber
Mot stated
tiot stated
!lone
33
Sun flashes on metal
or metallic
Roughly circular
At the distance and lone
altitude the object
appeared ~o be the
size of a11Ter dollar
ffll.1te or luminous.
·rurnod to be more
red aa the aun aet
Round teudi og to
be conical
Unknown - altitude
a.na distance too
great
Iona
~ot auted
Cone.
red
topped with Jot stated
lone
:53e
Si lver with shadow
Raindrop
Unlcnown - believed
to be lar~
lJnJcnoa
53d
1'h1. te
Round at time•
cone ~haped
-
Uneert&in because
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.
43 .rt. acrose
!lone
Redish tinge
Round
Large gre.pef'ruit
Ion•
35
Fire oolor
Ball
liot stated
llot atatecl
36
)lot stated
Bot stated
Mot at&.ted
Bot stated
38
Reddish with blue
background..
Black
with white baokground
SilTer
lot stated
Ball
S ft. from point of
view
.Not ate.ted
lone
Mot stated
NND 927545

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.
Aluaim"-
Round
3 tt. diameter
lot atate4
"1
~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.
lot stated
lot 1tated
48d
Yellow or tlame Rot 1tated
colored.
49
Not atated
Pencil shaped ob3eot
!lot ■ tated
lot stated
t

cot~FIDENTIAL
Incident
10.
color
Shape
Si•e
sound
50
Stated aa
queer 11.&ht.
Referred to aa aauoer
but not stated as being
ot thie detinite shape.
Kot stated
Jfot atated
51
11lver
Bomd
Not stated
•ot •tated
52
llhite. ah1Dy
Circular like a ball
en the bott011 but not
completely round.
15-25 tt Diameter
!lot atated
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
light
Round
2 :tt. d1aaeter
Hone
lfot stated
Kot atated
58
Blaok
Saucer (not det1n1tel7
1tated •• being tbia
shape)
Larger than C~4
airplane
Not stated
59
Incandescent
11Cht without
appreciable
blue and no
redd1eh tinae.
Hot stated
Not atated
Hot stated
60
Plame oolor
Diec shaped (the 11'ter
glow •de 1t look like
a oone)
Barrel Bead, dinner
plate am the aise
ot a plane tl71,ng
hi&h.
Wot stated
61
White ancS
111Ullinated
Bot stated
Sue ot Pigeons
lfot 1tated
62
YelloV1ah
vhite
Bot stated
811811
Mot stated
Gleuaed and
Shialered
D1so (not actuall7
stated aa being ot
this shape)
, rt. a1aaeter and
ot no great th1ok•
neaa.
lot stated
64
Color 111111ar Kot stated
to eiectr1c 11.&ht.
lot stated
Hot stated
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
57
h1ghl7 po111h- ournd-larger 1n front
4
ed chi-Ollium.
than 1n the rear .
:~e:O-l 1nchea liOMflDENTIAL
NND 927545

•
flDENllAL e
Incident
68
ColOJ'
Hot stated
Shape
I
D1eo - appeare~
a tail.
to have
UU.
30 tt d1aaeter
sounc1
lone
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
1auoer or diac.
2·3 tt diameter
Rot 1tated
Deep Gold
1111pt1oal
15 tt long 2·3 tt
1n length.
lot atated
74
Bot stated
Tapered lbarpely to a
point in the tront end.
,o tt. diaaettr
Hone
75
Slq blue
Oblong like a broad rill
hat with a low crown.
20 tt. lona am
10 t,. thiolr.
Kade a
av1shiq sound.
76
Not stated
Jot 1tated
Hot stated
Lite the eoho
ot • aotor.
77
Light colored
Only oonerete evidence
50•100 tt lfide.
or tora appeared on the
lett tangent ot the group.
Loud roar
78
Light gray
e1rou1ar
8 tt. diueter
Bot ■ tated
79
S1lftl'
Bot atated
Lu•er than a
Pibal balloon When
obaened through a
theodolite.
Not atated
80
Retleoted vh1te
light.
"Blob
11
SMll ail"plane
Hone
81
S11Yer
'
Large Balloon With silver Large
d11c below it, no attaebing
cables vere noticed.
lot etated
82
Proat7 ltbite
Round and tlat
Equal to b\11.k ot
6 eaob, B-29 air·
planes tdth dia ..
•t•r to tluomeas
ratio ot 10-1.
A 1l1gbt
mahing.
83
Black
Round
'tVtnt,-.f'ive cent
piece.
lot atated

,.DENTIAL e
Incident
110,
84
color
Sb1Jm7
Ship,
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
JotS1t&ted
Bot stated
lot ata.ted
lot atated
88
lot stated
1lying di ec (not ao­
tual ly deaoribed aa
being ot thi• aha.pe)
)lot 1t1.ted
lot atated
Ro\lDd di,o ahaped object 50-60 rt. diameter
bot at&ted
Refleote4
light
Unitonn with no protu­
berano•• euoh •• wing•
of an airplane
Hot atatad
Bot 1tt.t1d
Light
lot atated
Not stated
looe
92
Silver
lot ,tated
S-11
lloli ata.ted
94
Bluish center Appeared to be a
·.rlth rod on
its edgH
!ot atatad
lot 1tated
di10
Reaembled ~ shooting
at~r; however. ob­
aervera not oertain
Not stated
Not etated
Not ,tated
95
Not stated
Not stated
Kot stated
Bot stated
96
Not st:i.ted
Hot etated
Not stated
Not atated
91
Flaah of
light
Kot atat••
Hot stated
Hot atated
98
Bright light Ahaoat round or perhaps
oval or aauoer-ahaped
2ti-30 miles diametor lot etated
99
Shining
Brightly ehining object
with long td 1
lot atated
Bot atated
100
Wot ,tated
lot atated
!lot stated
NND 927545

-COt~f\DENTlAL:­ e
-
Incident
No.
Exhaust
Trail
Heading
Altitude Ft.
Speed
lffect on Cloud•
l
t:one
320°
1000-sooo rt.
~00 mph
lot at&ted
la.
lb
le
Not stated
liorthwest
7500-8000 ft.
~50-400 mph
Hot stated
ld
f.ot stated
northwest
7000-8000 f't.
300-400 mph
tlot atatod
le
tlot stated
tiorthwest
6000 rt.
300-400 mph
~ot stated
2
tot stated
Not at&ted
From very near
the ground to
vory high
Not ste.tod
llot atated
3
Not ata.ted
frost to east
10000- 12000 rt. 200­ 225 mph
)lo-r; stated
4
Not stated
North of due
east
Under 20000 ft .
Slower than Hot stated
lllAXimUDl speed
or P- 80
5
Bot stated
Two flying
aoutb - S
flying ea,t
Bo'\ stated.d
Great speed lot atated
6
Not stated
llorthweaterly Undetermined
Terrifie
lot stat.d
7
None
Southweat
50000 fto
Terrific -
faster than
any object
ever seen
by him
lot stat.cl
8
8a
9
Rone-
Jlone
Not atated
South
South
S01..-th
40000 tt .
40000 rt.
High over
Globe Mille
Terrific
?errifio
Terrific
lot atated
Not ,tated
lot stated
10
!Jone
Northwest
llot stated
Cruised for Not atated
46 min. at
oonventional
airline apeed
(180 mph) then
rapidly dis­
appeared
11
Not stated
OTer north end lot stated
ot Lake 1'o.sh­
ington
llot stated
.ttoi; ata.ted
CG."f,DENTIAL
NND 927545

Incident
Bo.
12
14
15
16
17
18
19
20
21
22
23
•
F1DENTIAl
E:xhauat
Trail
Wot atated
Bee.ding
Hot stated
.lltitude Ft.
Not atated
lot atated
3 west to
eaat.
l north
Did not appear
Tery high
lot atated
lot atated
Iot 1te.ted
lfot 1tated
l beaded
s outhea1t.
2 headed
north1a1t
.lot atated
High
lot 1tatad
lot ete.ted
north to IOUth 9500 rt.
about 17<i'
Trail atreaa- aeenronr
Jiot atated
1ng out be-
weatend
him like
of Toronto
vapor trail
'beh1m air­
plane on
misty day
Lim alight
eat to east One 11.ile high
trace ot steam.
Disappeared
1m::nediat•ly.
Not atated
Southwest
About 1500 rt.
Rot stated
~.N.W.
1200 ft.
Bot stated
S.W. ot S.
7000 tt.
Not stated
!lot stated
5000 tt.
Cloud-lie
8outheut
Very high
n.por - re­
tained shape
a.nd persiated
tor onr an
hour
Spoed
Effect on Cloud.a
lot •~d
Hot at&t.<l
Tranlini BO
taat they
•ere out ot
llot ,te.ted
eight in eaat
in 2-4 aeoonda
JloT1ng slowly llot atat.d
onr aandy
dletr1ct
Sot atated
lot atat.d
!tot atate4
llot atated
Not 1tated
lot 1tated
Not stated
Hot stated
Very taat
Bot stated
Faat
llot stated
About SOO
lot atated
mph
Slower than lot atated
two-motored
U1lY plane
lfot ate.ted
lot stated
Very tut
Mot atat.d
\
NND 927545

•
CONFIDENTIAL e
Incident
Ho.
25
26
27
28
29
30
..'
S0b
300
SI
32
33
33a
B.xhaust
Trail
Heading
Altitude Ft.
Wot stated
Bast
High
Bluish-black Not sta.ted
Bot stated
Bluish-black Not stated
10000 ft.
15 mi. long
Not stated
Not stated
Not stated
Not stated
10 flying
High
north; on
reverse course
there were only 7
None (ap-
West
3000
peared to
ha.ve bluish
streaks out
t'rom aides
Five times
1200
Prom .,ery near
length ot
g?'Ound to 1000
object
Small streak 8.8.Wo
trailing object
Wot stated
Kot atated
di!teNn.~ al•
titudea ;
White., heavy West to eut
20000-50000 ft.
lone
Stationary
3000 tt.
lone
lone visible
Unknolm
Jfone
210° from
Extremely high
Godman Field
None
Not stated
Not stated
Speed
Effect on Clouds
Fast
Not stated
llot stated
Cut a clear path
throup cloud•
Fast
Seemed to out
0loud1 open
Did not
moveo
Seemed to
go below
horizon
Bot stated
with rotation
of earth
300-400 mph
Bot ate.ted
Slow
Bot stated
500 mph
Jlot stated
rt. a,tter 1t
atartecl
to le&"ff
n.e1n1ty
bceeding
Bot ate.ted.
600 aph
Jfotionlesa
lot stated
~-~-----­
600-~00 mph Bot 1ta1;ecl • •
Stat1anary
"lone
nom n.aible Ione
Stationary
!lone
Not stated
Bot sta:t;ed
NND 927545

COhFIDENTIAL -
..
Ino14ent
Ezhautt
Jo.
Trf1l
lta4w
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
GodMn Jld.
••PJ higb.
throuab oi.ffU
,,.
lone
210• t'Poa
25000 tt.
Stationary.lone
Oodllan Pld .
,,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 atar.
IOJ"tbwaterl7
Rot atated
700-900 IIPh lot atated
,5
81.N• ot
tire.
lortbeaat
lot atated Jot atated
,6
lot atated
Jot atated
,1
lot 1tated
lortheut
aooo-10000 tt.
350111'h
lot ■ tated
JIOt stated
lot ■ tated lot 1t1t.d
,e
lot 1tated
lfa,t stated
Ion•
Bait
,0000 tt.
V0'7 ta1t lot 1tated
39
40
Kot 1tated
Appeared troa
5000 tt.
~0-600 aph lot 1tated
nOJ'tbeaat.
41
Jot atated
South
lot 1tated
Great
lot 1tated
lOOaph
lot 1tated
42
lot ,tated
Borihweat
1500
4,
lot 1tated
11rat group
1200
,oo mph
Jot 1tat14
S S/£, 8HOnd
group 1/V.
lot 1tated
South
lot 1tat1d
hat
lot 1tate4
44
lot atat•d lot 1tatecS
Jot stated
lot stated
lot stat•d
45
, ••tel"
lot 1tated
Jot stated
lortbwtatff1,1
1000
46
than an air•
plane.
10000
J'uter 11ml lot 1tate4
Jot etated
80'1thfllterl7
IJ7
•ftT aiNratt
h• ba4 rnr
•••n.
Gained an~ lot stated
Ga1eous green 5/V llhtn 1t
Mot stated
101t alt1t•
a11t.
lett the
'f'101D.1t7 • NND 927545
udt at a
te1"1"1t1o nte.
60111 1uENTIAL

n u
NTIAL
?no1dent
10,
Exhauat
n:,11
leaflN
Att1\Jde Pt.
Spefd
Btteot on ClOlldl
4aa
ver, tatnt
S/1 llhen 1t lett
emaut trail the Y1t1n1tJ.
llben 1IO'fing.
lot 1tate4
Lett
Jfot stated
T10in1t)'
at nr,
h1gb 1peed.
Gl'eenlah
111st 1hen
deaoending.
S/W ldlen it lttt
the TlO1n1ty.
lot 1tated
lot stated Not stated
lot 1tatect
210 degree, lllben
1 t lett the Tic -
1.nity.
15000-20000
lot stated Hot stated
~d
lone
Approxblately
1l'011 4000 to
due nat lalen 1t Ter1 hi&b.
lett the T1o1n1ty.
Slow
Not stated
49
Lon, trail
ot Doke.
Vest
Very hi&h
lot atated lot stated
50
Kot stated
Shor•wrd
Rot atated but
•aid to be
quite close.
Slov until Bot stated
OTer land
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
lortolk
22000
Equal to
Not stated
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

»ioldent
lo,
57
58
59
60
61
62
64
65
66
67
68
69
70
71
rlDENTIAL
•
CO~
Bxbauat
m11
lltfflPI
il\1'1\4• ,t.
lo\ 1tated
DZ <,o• I ot
,o• ott the
true IOJ'th on
llor1son at
bor1.Sonal plane. an ••t1111ted
1,A 1111• rap.
lot 1tattd
1/W
1000
9500-10000
lot attted
,50- later
ohaJll•d to
1or.
Liabt tlae JPrca 1/1 bead-
6000
oolor.
1DI Eutwrd.
2000-,000
lot 1tated
lorthern
&e-nral
Jot atattd
lot atated
thOUlud tt.
lot 1tattd
lortheaaterly
3000
Jot 1tated
lortbeaaterly
lot atated
1000
lot atattd
Weit to la1t
Low
Lone atl'a-
lorth to South
tsht '4\itt
1treak 11.ll­
ilar to th•
1treak left
by• traoer
bullet.
500-1000
White bail lot 1tattd
of l■Okt.
6000
Wot 1tated
Southea1terl1
lot 1tateO
Thin 1treaJc South
of gl"e7ill\
color.
1000-,000
Bitber 1aokt 1B to SV
or conden­
eat1on laat-
SAI 2 1eoonda.
Jilt)' hav•
Southeaat then
wot atated
been IIIOkt
t\ll"Jled and vnt
or npor
net.
tr• 1nttnae
NND 927545
ltt1s\ on 212'94•
Jli,tl .el..
lot 1tated
001t7, 1ta­
wd toM
taatu t:bUl
• tnoer
\,ullet.
510 apb.
lot 1tattd
1000 lmota
lot atat.4
raster than 1'0t 1tated
,ua,.
Jl1&b rate
lot 1tated
of 1peed.
TrandOUI
Jot stated
Speed.
terr1tlo
Jot 1tattc1
1000•120011>h lot stated
Required ,-4 lot 1tattd
1econd1 to
tnffl 70•
an.
Tnr1tlo
lot 1tated
lot 1tated
lot 1tattd
Vff"f t11t.
lot stated
a.oo,oo
1ot 1tated
7ooteoo
lot stated
■i,eed WI
aiaoet wit•.

Incident
lo.
llxhauat
ffiil -
Bgd1ng
~hr r~eE·~flAl:
iiUuii i
i
41t1t1»4e Pt, •
Sp••4
Vtftt op Qlouf•
72
Iona
South
Below 10000
'flteaendou
Jot 1tated
1,
lone
Ba1terl7
approxillatel1
110• -,netio.
7000
175 IIPh
Rot 1tated
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•
approi111atelJ
25000.
Inaono~nblt lot stated
79
Jot atated
Batt to lfe1t
LIii t.ban 15000 Jot atated
Kot 1tated
80
Jone
southeast
Lesa than 500
CCIIIPUttd at
·1:550 IIPh,
hOWffJI IP•
pelNd to
aOTe "1th
tbt speed
ot • Jet
11.Jlcntt.
lot atawd
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,­
?idly
liot stated
89
llot etated
Eaet
11000
210 mph
JIJot stated
NND 927545
CONFIDENTIAL

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
Diaappeared
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
predominating
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 atated
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

lfOtE:
Inc1dent f 18
It has now been d•tinit•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
aggerated.. iugination and 1nol1ned to iJlpreaa people with his
continuous uhatter.
NND 927545

CONFIDENTIAL
REPORTED DIRECTIOIS OF PLIGHT
D
5
I
Circling 16
Straight down 5
Direction Indefinite 64
Direction lot Stated 61
2Z
34
s
• 1'he re an undetermined number ot ob­
jecta ware reported the minimum number
of object& are plottedo Same object
reported by di!'terent p,ople only
shown oncto
NND 927545
CONFIDENTIAL

,
NND 927545

(no extractable text)

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 giT~ 1n th• report.
l>.
Th• nport 1tatH th• objeot na •••n a.1- approxiat•ly 2000 t••t
at tho ti• ot expoaure. !he obaerHl" allO report, bein& abl• to Ht oltarl1
t. oanow of •nolo1v•. !h• Tiaual aouity 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

•
" NND 927545

•
NND 927545

THE AEROPLAtlE
18S
I
FEBRUARY 13, 194&
#
The Biolo!
of the Flying Saf cer- I
The Story of Low Aspect Ratio Aircraft
By A. R. Weyl, A.F.R.Ae.S.
other hand. the U.S. Air Force considered the matter seriQU\
S
EVERAL MONTHS AGO people on both side.. of the
enough to warrant inve..tigations into the incidenis which had
Atlantic rushed into print wnh claims of having ob~erved
queer saucer-shaped aircraft which new very fast. Some main­
been reported.
tained, indeed. that they had seen ,quadron\ of , uch mysterious
In the meantime. the occurrence of Flying Saucer\ ha.. ceased
ob{"ccts; others described vividly how these celestial saucers v.ere
to be new\. Presumably. 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 January 16 la~t under the
heading •• Tuppence Coloured."-Eo.]
Sceptics considered that, for non-aeronautical people ltv1ng
far from the former playarounds of V. I. V.2, and all the rest
Aerooaudc-al Aotlquities and lniquititt
of Hitler's "civilizatory • practices. flying saucer<; might indeed
As a matter of fact. saucer-\haped aeroplane.. are not quite
constitute phenomena of threatening aspect, from their experi­
Quite
ence of domestic disagreements. Doctors, however. hastened to
as new as some people have tried to mal.e out. (Fig. I.)
assure the World that saucer-shaped 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.. of
Greek letter,. pancal.e\, nat fhh. geometrical symbols. dinner
imbibing intoxicating liquors for the observations.
On the
plates, and other entirely non-aeronautical commodities.
Moreover. it is quite true. .and not even a minor secret, that,
at present. aeronautical engineers are paying increased attention
to s uch queer wing shapes: disc wings. for instance. permit
ceriain disadvantages of conventional 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
of 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
for soaring. designer, began striving after .. good .. aspect ratios.
The theory blinded their eye~ agains, the poss1bili11es of other
than convenrional wings. Thi~. 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
1L- I._
' _°'
, -r.:--i,
I
c 6)
- _____,_ _'°' _1 ______, ==~ (b
OCl5S• stCTIO!'I
\
,pa"
C chor4
t
\
)(•-,lod a,u
Fig. 1.-" Turbine flying machine" (project) of the Munich
engineer Gustave Koch, 189311894.
Tailless monoplane of
SquHC'
low aspect ratio. propelled by a ducted fan.
A SO h.p.
...~ ,
steim engine wu deemed sufficient for this flying motor
car. The design of the duct shows intelligent anticipation.
L
...._______.
AR • 0-1
I- b ,__j
l t t
Fig. 2 (Right).- Definitlon of the aspect ratio of an aerofoil.
The arrows signify the direction of the air flow against the
t t t
wing. The terms pteroid (feather-like) and apterold have
been introduced by F. W . Lanchester.
NND 927545

\
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 that
Nc11.ton's law wa, valid for these. 1he correctncs; of thi~
Fig. 3.-A simple experiment In annular .ierofolls.
vie\\ wa~ c~pcrimentally proved 30 ~cars later.
In a prev1ou\ article on " Stalling Characteristics 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-equalmng flow around 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.tcr published his bool.., man was ju~t begin­
main wing. the tailless aeroplane is created.
For all these
nma to_spre~d his wmgs. and in order 10 fly with a minimum
arrangements. the condition is that, in the case of a wina com­
ellpend1ture m power, wini:s of fair aspect ratio were a neccs­
s11y.
Neverthele\s, there were a few early aeroplanes. notably
pmed of normal (unstable) aerofoil ~lions. the stabilizin&
aerofoil exens a certain leverage in relation to the centre of
the little :· Demo1~lle •• monoplane of Santos Dumont (1909­
gravity of the aircraft.
19 !0l, which had an aspect ratio of only 2 and proved to be
quIle \Ucces,ful.
Another possibility is to combine two lifting winas so that
they will stabilize and balance each other. For this purpose, all
One o( the earlie~t attempts at a genuine •· apteroid" 11cro­
plane was an experiment by a German architect, Flick-Remig
that is required is that the front wing shall possess, at all inci­
dence, of.flight, a greater effective incidence than the rear wiog.
( 1910). It had a span of 7j ft .. and performed in hops only.
In other words. the centre of gravity must be nearer to the
le.iding wing than to the traili9g wing, and the whole arrange­
Annular Aerodynamks
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 diameter 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. Aerodynamically, 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 shapes con,titute the wing. For
acteristics of an annular aerofoil are certainly very different
,implicity's ..ake, in all such cases considered here, the term
from those of the plain d1-.c aerofoil. Our own experiment,
.. annular" 1, applied.
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.er 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 an 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 high angle~ of
\tblc one.
The balancing .ind st11b1lmng aerofoil (tailplane)
incidence are not likely 10 be reached an flight unintentionally.
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. or in front of it.
Another property of annular wings (first establi,hed by
If the balancing aerofoil i, in front of 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 of the
centre of pre,wre can be obtained which i, po,itively stable
unul incidences of 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 Kitchen. 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

FEBRUARY 13, 1948
187
THE AEROPLANE
flight of Kitchen'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
·JUI· tl?,!i m
hib energy 10 tbe idea of a ·• safety " aeroplane.
Tilghman Richards began with systematic experiment, on
__.._
models and on large gJiders.
Later, careful wind-tunnel test~
(including the observation 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 order 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 very 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 high lift/ drag ratio at
,mall an,les, and what is required is the reversal of the normal
type of hft curve i:iving little lift •lit small angles with low value
of the lift/ drag ratio for landini. . . ."
Seen from our pre.sent state of knowledge and development,
and facing the burning problems of personal aircraft for the
man in the street. it would seem that this opinion is a very
i;o~ argument for further experimentation along the lines
indicated.
_The. experience with _powered aeroplanes was at first beset
with disappointment~. Famine P_oint, Heysham, was apparently
not a spot from which aeronauucal experimenters could derive
any comfort.
The original Kitchen biplane with a 50 b.h.p. rotary engine
was wrecked by a gale, during I 9 I I. before flight tests could
b~ m~de.
After recort~truction some flight~ were performed
wtth 11 at Sho!eham <!~ring 1911-12: yet it never gave any
pr~~f of superior q~ah11es. The biplane had ailerons of the
or1gmal Farman variety between the wings.
Very soon the
biplane arrangement w!1s given up in favour of the monoplane.
A subs~quent experimental monoplane was nicknamed the
" Sccret-C1rct1: Plane ".~r "Doughnut,'' the experiments being
shrouded agamst pubhclly (much against the interests of the
dev~lopmen!),
This annular-wing aeroplane (Fig. 7) was
equipped with an 80 b.h.p. rotary and test-flown by Gordon
England on November 23, 1912. at Shoreham.
The flight
was _remarkable and luck>; for the pilot, but. unlucky for the
precious craft.
After havmg flown a large circuit on the first
attempt. the pilot noticed, when coming in to land that the
aeroplane was exceedingly tail-heavy and getting out ~f control
the elevator. bei!Jg insufficient.
At about 150 ft. above th~
ground the inevttable stall took place: but the pilot managed
~~mehow to drop his mount upside down on to telegraph
wire~ and escaped without personal injury.
Wtth the reconstructed and improved monoplane many
s\iccessful flights were made by Gordon England, N. S. Percival
-:'x:
- -'­
Fig. 6.-Huth annular biplane of 1909.
and Gordon Bell.
Finally it came to i;ricf when flown by
Cedric Lee himself without previous training. After a good
fliaht he managed to put it into a river.
Another incident happened with a subsequent annular
monoplane: the elevator jammed anct broke in flight.
The
aeroplane merely pancaked to the ground, again preserving
the health of i~ pilot, E. C. Gordon England.
These types in their final form had lateral control effected
by differential deflection of the elevators. It was realized that
this elevon control was not very effective for lateral manceuvres.
yet the lateral stability of the wing proved so great that the
provision of ailerons seemed superfluous.
The loneitudinal
stability was always satisfactory, once the centre of gravity was
properly located.
Because of the great inherent ·fore-and-aft
stability, a separate elevator was, at one time, located on top
of the vertical fin and permitted the fitting of special ailerons.
For directional control a vertical rudder was attached to the
stern of the fuselage at the trailing edge of the wing. A form
of tricycle undercarriage was employed.
-
In respect of performance, the wind-tunnel tests indicated
that a better lift/ drag' ratio could be expected than with a
comparable conventionaf aeroplane., However, no conclusive
evidence for this has, as,yet, been presented.
The third British monoplane of this type also had an 80 b.h.p.
rotary engine. but this time it was located aft and. further, drove
the airscrew by means of an extension shaft. Unlike its pre­
d~cssors, ~~ dihedral was provided. and because of this the
flying qualities were found to have been greatly improved.
From early in 1914 until the outbreak of the 1914-18 War
this unconventional aeroplane was frequently flown (mostly
by Gordon
Bell): it was demonstrated before Winston
Churchill in the hope of securing orders from the Admiralty.
Altogether, 11,000 miles were flown in about 128 hours, and
eve~ people not previously trained as pilots were able to
fly 11. In May, 1914. two such aeroplanes were being designed
for parlicipation in the Gordon-Bennett Race of 1915. When
the 1914-1918 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 an 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
aptero1d 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 without affecting the
general efficiency of 1he plane."
As _mentioned. 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 successful.
(To ~ conlit1u~d.)
Fig 7.-Cedric Lee Monoplane No. 1 of TIighman Richards, 1912.
NND 927545

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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.
T
(Continued from J>Olt 185, February 13 /rut.)
HE SECRET-CIRCLE "CONSPIRACY;• mentioned pre­
viously in connection with circu)ar-aerofoil aeroplanes. did
not lack congenially inventive spirits. Early in 1913 an engineer
in Dijon. M. Bourgoin. made experiments with an annular­
wing aeroplane. The tests were unsatisfactory. One feature
of this design was the provision made for varying the wing
incidence in flight.
More recently, a similar idea was suggested by N. H. Warren
and Th. R. Young (Fig. 8).
In 1937 they secured a patent
(Brit. Pat. Spec. No. 508,022 of December, 1937) for a non­
stallable monoplane of rhomboidal shape (i.e., leading wing
swept back and trailing wing swept forwards with the wing lips
merged together). This was provided with a conventional tail
at 1he stern of a long fuselage and a number of advantage~
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 triangular shape of each wing and the effect of
sweep was relied upon. Nothing more bas become_ known
since however but it is worth noting that the proJect had
been'based oa ;ound aerodynamic considerations.
lo 1933 the annular wing of the German sculptor Antes
created a mild s~nsation bc<:ause ?f the good performance oC
models made to this coocepuon (Fig. 9).
Some.what peculiar was the aerodynamic ~onceP.tion of the
rhomboidal annular aeroplane of P. Nesbitt W11loughby, a
=
Fis, 9.--Model of the "annular wing " ~f Antes. 1933.
qualified aeronautical engineer (Fig. 10).
The Willoughb}
Delta Co. of London had taken up the development of th,.,
idea in 1931 and sufficient means were available to make rather
extensive tests.
The principle is best described as a tandem monoplane with
two aerofoil-shaped parts connecting the leading wing with the
trailing wing near the tips. The "side wings" had aerofoil
shape not only in their longitudinal cross-section (i.e., in the
direction of flight). but also laterally. This was considered a
characteristic feature and subject to patents. It was claimed
that the vortex distribu1ion induced by such shape gave an
unusually high aerodynamic efficiency in spite of the small span
of the aeroplane. In addition. it was pointed out that the
maximum lift was shifted to very high incidences.
Moreover.
the "side wings" should reduce the drag of engine nacelle,
filled underneath them.
All this was said to be proved by extensive wind-tunnel
experimentation here and abroad.
Designs of passenger trans­
pon aircraft reaching weights of 40,000 lb. were prepared on the
basis of model tests made at the National Physical Laboratory
and elsewhere. The results must have been so encouraging
that an experimental monoplane with two 125 b.h.p. Menasco
engines 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 crash 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
longitudinal inslability and it is not improbable that this and
poor control efficiency may have contributed to the accident.
There was also 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).
1 1
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 properties 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, may 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 on normal aerofoils tests were restricted to rather
small incidences only. generally ucluding the range of stall.
NND 927545

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MARCH S, 1948
THE AEROPLANE
280
c
>
\
I
\
I
I I
I
I
I I
\,'
I I
\,'
Fig. 11.-Willoughby's "Delta 8" experimental
monoplane of 1938.
Thus, an observant student of laboratory tests could have
noticed the extraordinary capacity of circular or square shapes
10 give a very gradual, innocent stall, an~ that at v!!rY high
incidences. Yet, apart from a few broad-minded experimenters,
no designer drew the conclusion that wmgs of such shapes
promised safety in flight, t~oug_h it w~s known f~om ..~rly
practical experience that fly1Dg 10 the
second regime,
1.e.,
at the stall, was positively dangerous.
It is true that spinning- Parker's "Spiral Dive "-was
attributed. in those days, to high i~cideoces, and that most_of
the lightly loaded rectangular wmgs used at that period
rendered the stall relatively. innocuous.
Howeve_r, :iccidental
~tailing was then, as now. the cause of the maJonty of all
crashes. And the nose dive following inadvertent stalls was well
known to be of the most serious consequences.
.
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!).
Eiffel 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 (exceeding a value of 4) the maximum lift
took place at incidences of 12 to 14 degrees only.
Beyond
their critical incidence disc wings gave a gradual decrease of
the lift force whereas wings of 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 different manner from one
having an aspec't ratio of 1.5, although wall interference and
Reynolds Number may have somewhat affected the results of
the tests.
.
Later, Prandtl was eager to point o~t that his aer~fo1l theory
did not hold for very small aspect ratios, and that, ID fact, the
induced drag of disc wings was less than the theory suggested.
In sP.ite of this, however, nobody seems to have he~ded the
possibilities implied and the " ~attle of the Aspect Ratios" was
decided in favour of slender wings.
.
To be fair, it must be pointed out that there was one senou~
I
Fig. 12.-Experimental Hayden glider, 1925. Span, 19.7 rt. :
length, 13·85 rt.; wing area, 173 sq. rt.
All-up_ weight,
310 lb.
No lateral control.
argument against disc wings. The best aerofoil sections in use
prior 10 about 1925 had a plain camber which implies travel of
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 or 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 already been used in flight which
had practically no travel of the centre of pressure and hence
did not suffer from thi~ disadvantage of the disc wing.
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 disc-wing
aeroplanes.
F. Handley Page converted an aerofoil, leaving an aspect
ratio of 6.25, into six square-aerofoil portions 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 disc-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 disc wing and you cannot
have the benefits of the high drag without suffering its disad­
vantages.
Moreover, in order to have the effect of the disc
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
practical aircraft designer had realized that there was some­
thing in wings of abnormally small aspect ratio.
There were other. although not quue as well thought out,
antecedents of the disc-wing aeroplane.
In the tint soaring­
flight competition on the Rhocn ( 1920), Friedrich Richter, a
burly naval pilot of 20 stone or so, performed on a triplane
glider with wings having an individual aspect ratio of far kss
than three. H. Hayden secured, in 1922, a patent for a rhom­
boidal wing with an aspect ratio of nearly unity, claiming for
such a shape high lift and good flying qualities.
In 192S he constructed a glider with a win, having an aspect
ratio of only 2.25. The wing was nearly tnangular in shape,
with its apex leading, and a pronounced wash-out towards the
tips (Fig. 12); no lateral controls were fitted.
The tailplane
with the elevator was fitted underneath the trailing edge at the
c
==---=-­
Fig. 13.-A French project of G. Abrial, 1929.
stern of a f11selage.
Flyinf experiments in Styria were said 10
have proved satisfactory flying qualities.
Some early tailless aeroplanes, such as certain experimental
types of Rene Arnoux, had rather stub wings and heavily
reflexed (i.e., positively stable) aerofoil sections. A 19?9 design
of G. Ab rial showed an aspect ratio of 2.88, with, however,
substantial tip discs (which have the effect of increasing the
aerodynamic aspect ratio) and wind-tunnel experiments indi­
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
and IS).
Their resemblance in shape to the latest designs of
super-sonic aeroplanes is remarkable.
.
A Modttn Pioneer
Further intcre~t in the aerodynamics of 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, and performance estimates were based on the properties
of such wings.
Yet the question of stalling stability did not
arise, 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
Aeronautics (N.A.C.A.), who proved capable of following
independent lines of development.
In about 1930 Charles
H. Zimmermann subjected the properties of disc wings to
NND 927545

MARCH S, 1948
281
THE AEROPLANf
e
wing , tructures as well as for the pos\lbility of housing every·
thing w11hm a wing.
Hence 1hc1e are very real design reasons for the preference
of disc wings, quite a pan from the ea~cd accommoda11on of
short-span aeroplanes.
Some Rernurkable Results
Zimmermann establ.shed that the optimum a~pcct rauo "'"~
found bet,..een the values of 0.75 and 1.5.
l he,c value,
include both ,quare and ctrcubr wmg ,hapes.
For a g1Hn
wing sccuon (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 of 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
7
fool-proof aeroplane for amateur pilots.
It is no u<,c hiding
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
I I
On such very sound lines (which seem to be generally
acknowled$ed, but still far too often ignored), Zimrrcrmann
I I
directed his main attention to the stalling 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 " vortex 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,
however, 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 reduction of the
-1....____..._
.,,.
JO'
-:
relative thickness of the aerofoil sections. 1 his drag reduction
has indeed become one of the rr.ain reasons for di.c wings
being adopted for aeroplanes capable of flying at ~reeds at
which the compressibility of the air needs to be considered.
Fl&, 16.-N.A.C.A. tests by C. H. Zimmermann which prove
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 of 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 differ 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
aeroplane flattens out 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
power 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 three degree,: it increased to 17 degree,
at 126 m.p.h .. while the \tailing speed was I IS m.p.h.
Thi,
pronounced , teepcning of the g)idintt anttle makes a mer~er
hct""ce~. the aeroplane and
the helicopter an attrac11ve
,
propos111on.
.Another occulia_rity of . !he di~ wing cstahlished
b~
Fie, 15.-A ' puabola ' aircraft by B. I. Tschennowsky
NND 927545
.
Zimmermann wns us scns111v11y to the , hape of the wing•ur,,

--
10
282
'
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
to drag, as well as to other qualities.
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 of 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.
•
Pancakes Ii la Zimmermann
The results of Zimmermann's research were so ~onvincing
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
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
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
parasol monoplane with a completely circular win$, a camber
flap in the trailing edge and severely skewed ailerons Wl?.$
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·
burgh, Florida, an eminent aeronautical engineer of Austrian
origin (known as the first to prove-in 1913-that the r:itio
C '/C 9
governs optimum climb and glide with minimum
L
D
sinking speed, took up development of the disc-wing aeroplane.
Hoffmann's Flying Saucer was a tailless aircraft with an
aspect ratio of slightly over 2.
The fi rst type was an ultra·
li$ht single-seater with 36 b.h.p. Later a side-by-side two-seater
with an 85 b.h.p. Cirrus engine was constructed and flew well;
the wing tips served as ailerons and the elevators formed part
of the trailing edre.
The aerofoil sectir,ns employed were
N.A.C.A. M.6 basically. with N.A.C.A. M.1 at the tips. Both
are sections designed by.M. M. Munk. The former is a reflexed­
camber section with a practically stationarY, centre of pressure;
the latter is symmetrical
The central structure of the wing, the fuselage and the fin
was of welded-steel tube; the wing had three spars.
This
little two-seater }"as stated to fly well and to exhibit ve_ry go(!d
stability.
It seems, however. that the controllab1hty, m
particular directionally, was not satisf~ctory.
1 he visi(?n fr(?m
the cockpit must have been very restncted--a moot point wllh •
all these designs.
A speed range from 28 m.p.h. to 13S m.p.h.
was claimed.
The empty weight was given as 900 lb •• and the
wing loading was 5.5 lb. / sq. ft.
One remarkable characteristic observed during the flying
tests of Hotrmann's aircraft was that, when comin(! in to land.
the approach was steep: yet prior to the fl lltening out and
just before touching down, the glide flattened.
1 his would
l MAJ(
C
jc
Cl MA.(
0 MIN
r­
0 MIN
,001----.U---4---1---4----4-----+---~
CI..Akl( T AUl,OfOtL SfCTl()N
C,.ACA • IP No u,)
z
;•f
..,
.,,.
~
60
~
J
::,., l5
r " •
"< .. "
fl"
It .
!i "'
z
J
~ •>
• It
~
"
It
ti
0
11f
2
10
z
c!, "
~
6
t i;
AA
o·
•
ASP(Cf U flO ( •' 1J
Fig. 117.-These resulu from Zlmmermann's wind-tunnel
tests on disc; wings (1932) clearly show the character!stits
of low aspect ratio aerofoils.
•
MARCH 5, 1948
c:,_
i
g:
0
10
"<
Cl ARK I AEAO FOtl SECTION
"'
0
(i-v-CA
ZIMME~MANN,
..
~l P No ()1)
:;
o'----~---L---JL_.__..L.__...L._......:~,
ASPECT AATIO
., .,
18.-Furthcr results from Zimmermann's tesu shown here
also indicate the advantages to be gained from disc wings.
seem to. contradict the experience referred to above and it
w~s aunbuted. to. a ground effect arising from the rak~ of the
wing-tips.
It 1s indeed rea:.onable to e)(pcct that the presence
of t_he ground would affect the formation of the marginal
vort1c~s to an ex\ent which may markedly influence the
beh~v1our of disc wings during take-off and landing. Hoffmann
proJected a ousher and a twin-engined version but these types
did not materialize.
•
A
further development was the Arup monoplane of
R: J. Hoffmann and C._L: Snyder at South Bend, Indiana. The
w!ng _shape ~as v~ry s1m1lar.
I~ resembled a semi-circle flying
w11h 11s straight side a_s the_leading edge; to this wing, ailerons
were added as special ups.
1 he aspect ratio practically
corres~onded to. that of the previous Hoffmann types.
Again,
aerofoils wtth little centre-of-pressure travel were used.
1 he latest type ~ad it~ _tailplane and elevator separately
locate~ over the wing tr:11lmg edge (similar to the .. Elytro·
plane
of De Rouge!).
It seems that the longitudinal control
at certain incidences was not satisfactory.
1 he ailerons which
formed part of the wing shape and reduced the aspecl ratio
to a value ~f I: 15 had a triangular shape and were greatly
s_kewed (taking_ into account the obliqui: flow over the wing
tips). The engine was a 70 b.h.p. Le Blond radial; a tricycle
undercarriage was fitted.
With the oilot alone, a gliding speed of 23.S m.p.h. was
r~o_rded (lhe wing loading was about 3.3 lb./sq. ft.) and a
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 without nattening out of the glide.
1 he maxi·
mum speed was 86 m.p.h .. and the take-off was stated to require
S secs. in zero wind.
Several more Arup types seem to have been constructed
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
development ceased abruplly.
It is worth noting that Charles
Zimmermann himself has taken no part in this development,
b1;11 he was an interested spectator at demonstration flights
wnh an Arup monoplane at Langley Field.
An Italian "Tortelllno "
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
secured patents for a rhomboidal wing, one diagonal of which
coincided with the direction of flight.
1 he ailerons were to
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
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
submitted to flight experiments.
NND 927545
(To ~ confin~d.)

,
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
W
I 0 -·1UN l· L I F-••n S w.:rc made in I unn and at Rnme
of five C:anovo1 project\ {de-.cnbcd m the prcvtom tn\1,11­
"'!Cnl of 1h1, ar1de). It " in1erc,11ng 10 note that 1he Canov.1
d1-.c-wmg lype, did 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" with two engines.
authorities to change 1hc1r minds and 10 terminate this
It crashed while under test (1938).
development.
1
A Return to Childish 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
an 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
more has been heard of Payen's cffoA~.
and made better use <>four schoolbooh than we ever expt-ctcd.
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. radial engine. An 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 triangular tail was fitted: the wing alone had
The helicopter-aeroplane is not a novel idea.
Many }Cars
dihedral. and the overall aspect ra1io was about 1.76.
No
ago, for in,iance, Nicola Te~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 cannot be adequa1ely dealt with.
In 1921 Claud Dornier ~ecured a pa1ent for a eonvcnlmnal
-
- ·-~
1/lO C
1110 C
L
Fig. 20.-Llft and
.__._
GI
drag of wings of
lL:
different
aspect
f 120
c• t
• 0
ratio. (Left) Wind-
\
~
. :
tunnel results
I
'--- 100
,_
obtained
at
Goettingen , in
~j
1920; Goettingen
-
389 aerofoil with
n
...
~~ 80
10 per cent. thick­
~ eo t--t--;illt":!'-~ -+7"lr--+--+..-t---c¥~--+~
19"
ASPECT RATIO
ness and square
~
.»
0
1 SQUARE v, ING
wing tips. (Right)
"
...
2
A reduction of the
1
0
...a:; ~60
+
r esults to an
A
3
~
~(
aspect
ratio of
...
h
'
w 0
(t
fi ve.
by t he
•
1·
._u ,o
0
5
Prandtl
Aerofoil
Theory
of t he
6
:::; t
4l
Induced d rag ,
()
7
s ho ws t hat a
~ w
squar e
aerofoil
(aspect ratio of
.t
one)
does
not
oQ-"11~t---t--t--:,~o- r-+ ---l- +-~ 20-+--+--I
I D
follow the theory.
- i--c
I
-
I- 0 i€
I
Its induced drag is
ORAG C0EfFICIENT
100)
10
20
less
than
pre­
I
~
I
I
dicted
by
the
DRAG COEFFICIENT < 100)
"h orse-s h o e
'--
20
vortex " assump­
0. : I
tion.
NND 927545

THE AEROPLANE
. 338
MARCH 19, 1948
•
t
L
l
100 C
AR 1
LA>­ ...l'
1IO
~
--;? ~:a-: L-/
L,CI" ,_,...
f
i\ ~ ~ /
~ 100
I
- ,
AR~
...:z
~Vv
V
~
~
80
~ ~ ~" Lu
V
V
,.I.
00
,, '
t:
't..
::;
/
J v v l,o'
'°
1,,1" fif (r
l.,o'
~ v
.#J~
cf
1-► (l
10 °
10
o·
I
.,.
­
0 '
•NGt[ or INCll)[NC( ( O!GRCES i
10
...
~
aeroplane with take·off as helicopter {Brit.
Pat. Spec.
No.161,948). Earlier still (in 1916), the German, F. Bendemann,
a noted fesearcb worker on a1rscrews, conducted a secret
development of an aeroplane with a large tilting airscrew
capable of rising and descending as a helicopter.
The
development of this air observation post was later discon•
tinued in view ot the Austrian helicopter experiments by
Th. v. Karman and Petroczy.
From
his
early
experiments
with
lifting
airscrews,
F. Bendemann found that hoverihg without forward movement
could be achieved- when the power loading of the aircraft was
less than about 9 11,../ b.b-.p.
With fighter aeroplanes, such
low power loadings were already then being approached and
1
operational experience bad indeed shown that certain single·
sealers could. under favourable conditions, be held in attitudes
approaching that of hov.ering (later the Fokker D.Vll biplane,
with a large airscrew, became renowned for this trick 10 air
combat on the Western Front). Attempts to revive the project
~ta later date failed. and with the suicide of its promoter (who
had gone into the Civil Service), all interest lo the development
ceased.
•
Charles W. Zimmermann, mentioned earlier as stimulator of
the disc wing, approached the conception of the helicopter
Aeroplane on the basis of his results with low aspect ratio
wings.
He secured basic patents and constructed during
1934·35, in the cellar of his home, a man-carrying aircraft of
bis design.
This had a wing of only 7-ft. span, with two
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•
Vought Aircraft Division of the Unik:d Aircraft Corporation
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 of
a safety-first aeroplaoe for the private owner.
The U.S. Navy,
however, took an interest in the possibilities of the helicopter•
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
practical.
The principle is that, at high speed and when cruising, the
aircraft shall fty as an aeroplane, while for slow speed and
hovering it flies as a helicopter.
Hence the airscrews are at
the same time rotors and must have a rarher large diameter.
With the V-173 the problem of the prone position for the pilot
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
and a fia),ter for use from aircraft carriers bas been the Chance·
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
claimed; in general, it follows the V-173 model. (See p. 185,
February 13.)
The aspect ratio of the wing is lesa than unity.
Strictly
speaking, however, it is not a genuine tailless aeroplane because
of the attachment of a trimmmg elevator to both sides ot the
wina. The reason for such excrescences is the need to locate
I
I
Fig. 21. -
LI ft
100 Cl
curves of aerofoils
t 1,10
--
of different aspect
ratios.
(Left)
~· O+
Wind -tunnel
-l
. o,."'
..
C
results obtained,
~- 100
­
in 1920, at Goet•
o"'f3.
I
tlngcn, w ith
I A .
Goettlngen
389
eo
~
ASPIC.T RATIO
aero fo i l and
~
a
1 Aou,hf
square t ips. The
0
?
WING
absence of stall at
t
V
00
+
,__ ,__
.0.
J
normal Incidence
::;
Is In evidence, for
b
• •
aspect ratios up
.o
I
,__
to a value of two.
I
­
t:
'° t
I+
..
ro
~
(Right) Reducing
() ,·
the values. by the
Prandtl theory.to
,,.
an aspect ratio of
five, shows t hat
wings
of
very
10 •
10
small aspect ratio
- - <
I
AN(;l[ Of tNCIO(N(( t OIGRH\ I
do not follow the
IO
theory in respect
of the induced­
Incidence correc•
tlon.
control organs directly in the slipstream of tht: paddle-like
airscrew rotor... The twin rudders, too. are in the slipslfeam.
Unlike the V-173 type, the XF-SU· l has an all-moving tail
surface and the undercarriage is retractable.
This interesting hybrid has a modern metal structure.
Two
Pratt and Whilney R-2000-2 engines Qf 1,350 b.h.p. each (at
2,700 r.p.m.) are mounted within the wing, entirely buried and
cooled by forced draught.
Water injection for temporarily
boosting the oower is one of the engine features.
A special oroblem was the design of a transmission ~ear
which allows both rotors to be driven from either of the eogmes
- this is a necessity in case of an engine failure.
The four·
bladed rotors are contra-rotating so that there is no residual
torque and are ,eared down to about one-fifth of the engine
speed, hence their substanlial diameter.
The wing loading is
rather high. reaching the order of 40 lb./sq. ft.
The Real Flying Saucer ?
Since this experimental type was produced, further progress
has been made in the development.
IL seems that axial-flow
gas turbines have been installed, and it is quite possible that
a combined oropulsion with thermal jet and airscrew rotor
is alt:eadv under test.
Wilh this, for slow flight (take-off,
climb and landing) the rotors are driven by the gas turbines,
while at high speed the rotors are declutched and feathered
and pure jet propulsion is used.
This would, incidentally,
(
~01! 1---1---1------.1---1----1----1
;
0
~ -
,.
<
i
Q
:::
...­
NACA 14 SEC11C)N:~
iS
V
..,
0-00,
._N•'1·1 , 10'
~
0
0.~L T!HI
i ,. ~
...
I
~
T{C
~ -
~01
0-ll
0-16
~IO
0 •1'
AU,0r0tL TMICKNESS A.ATIO
Fie. 22.-lncrease of profile drq with section thickness, at
:zero 11ft.
The lfnporunce of the tip shape Is obvious.
The data refer to an aspect ratio of flve (From D.V.L. wind-
tunnel tesu at low turbulence).
NND 927545

~ ARCH 19, 1948
339
THE AEROPLANE
.,...
M. B. Morgan has recently communicated the following
0·3 r----------------------i~
values for the limit of stability at the stall from this araph:­
<=o,
0
Upper llmic of th• Ansl• of Swetp,back (r•lerred
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
6
14
••
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.
04
as ~ res!lll, the rare ca~ i;,f two quite different aspects of an
o-a
1·0
enginee~ing_ problem pointing to an identical solution.
1 he incv11able result has been the development of arrow­
sh<;1ped:. more ?r less triangular, . disc wings, termed " Oelta­
Fig. 23.-lncrease of xero lift profile drag with thickness ratio
Wangs, _for lhgh~ at sp~eds which are trespassing into the
of symmetrical aerofoil sectldn. The saving In profile drag Is
tr~ns•s?nlC
velocity rtg1me. Another advantage of such
one of the advantages of disc wings because of their thinner
wings as that when the shock stall occurs. the backward shift of
aero~oll section. (Data from Gerber, Zurich Report No. 6).
!he centre of pressure is less than with normal wings. The
induced drag doe, not count quantitatively at tbeg high speeds
explain the extr~ordinary ability of the reported •• Flying
Development of such abnormal aeroplane types began i~
9e:many during the War_. following the progress accomplished
Saucers·• to be able to fly very fast and high, and also to hover,
•~ 1et and r~ket propulsion since 1937, which had shown that
ascend _and de_sceod with practically no forward speed.
No
flight . at sonic vcla<:IIY wa, a r,ractical proposition.
A few
~ther a!rcraft 1s known to do that.
On the other hand, it is
ll!(ODCeavable that whole squadrons of such unconventional
experimental delta-wing types had been brought to initial flying
te~t, when the War came to a close.
atreraft could already be observed at air exercises.
It is rare
. The German ~evclopmcnt had two distinct aims, resulting
for military developments to progress as quickly as all that.
11_1 two separate hn_es of approach. The immediate target neces­
. For operatao~ with gas turbines a speed range from zero
satat~d by the Allied bombing raids. was the creation of very
(1.c., hovcrin~ flight) to more than .500 m.p.h. has been claimed
fast Jct fighters or fighter-bombers which could surpass in speed
for
t~e Chance:V~ught-Zimmcrmann
helicopter-aeroplane.
even the Mc 262. _Secondly, there was the long-term develop­
Technically. there 1s httlc reason to doubt that such an amazing
spec<! range can be attained with the combination power plant
~ent of a supersonic aeroplane capable of flying over very lon11 \
d1sta~es. such n, from Europe 10 America and back. and
menuoned.
Jncidcntally, as there is not as yet a standard term for the
dropp11_1g a born~ or two ~n the way. Jt i, perhaps not too
fa_ntastac to surm1,e that t~•s development had some connection
combination of an aeroplane with an helicopter, the name
with the research on atomic bombs and bacteriological warfare
•• helicoplane •• is tentatively suggested.
The. oth~r line of engineering approach which has led to
instituted by the Hitler Gang.
For th~ immcdia!e. target, orders for interceptor-fiahters were
the da..c-winl! aeroplane of near-saucer appearance derives
from the trend towards very high flying speeds within the sonic
placed wath cnterpming firms, notably with the Honen brothers
and Messerschm111 (both pets of the Rcichsluftministerium) with
range of velocities. and in panicular1
at great altitudes. As now
the Gotha Works, ttenschcl, Junkers, Heinke! and Arado (a
commonly realized, the compres,ibi ity of the gaseous medium
sets a speed limit for conventional aeroplanes.
This limit is
G?vernment cntcrpra~). etc. In order to facilitate experiment~
reached when the speed of flight approaches sufficiently to the
~•th rather unu~ual aarcraJt ~ypcs and to enable an exchange of
veloc11v at which sound is propa&3ted through the air.
This
ideas.and expenences, a special research aerodrome was built at
"acoustic velocity" depends solely on the air temperature. and
(?ranien~urg (near Berlin) with all facilities for flight testing
is, therefore. lower at altitude.
Hence. compressibility effects
(in ~anacular, ve_ry l~ng wide runway, and workshop, for
begin to be felt at lower speeds when flying at altitude.
repairs and mod1fica11on, were provided).
This was placed
When the "shock stall," due to the compre~sibility of the
under th~ command of a capa~I~ _technician, Lf.-Col. Kncmeyer.
On this aerodrome, all the in111al and development tests with
air, ,;cts in, the lift is catastrophically decreased (hence the
novel prototypes had to be made. When the Russians collected
justification for the expression "shock stall "), the dmg ri,cs to
enormous values, and the longitudinal ~tability i, grossly
the aerodrome, they were agreeably surpri,;ed to discover some
impaired by a rapid backwards shift of the aerodynamic centre
of the most progressive aircraft ever constructed. It has since
beco!11e cenain that thcr have made intelligent use of this aero­
a~ well as by fluctuations in the flow pattern at the wing. The
nau11cal treasure as wcl a, of the technicians collected then and
experience of phenomena of such distressing nature has given
rise to two distinct aims in aeronautical rc,carch.
One is
afterwards.
Of the German firms interested in the develop·
ment, at least one. the well-known Junkers works at Ocssau has
to delay the ono;et of the phenomena to higher Mach Numbers;
the other aim i, to find wings which would permit flight within
been complete!y t!"llnsferred ~o Russia, lock, stock and barrel.
Most of the sc1cnt"_ts and ~e 1snen were urged to volunteer for
or throuF,h the tran,-sonic regime. The alternative. " within or
through,' is still a necessary impediment of definition, since
developm~nt work 11_1 Rus~m. Fe~ could afford to refuse.
we do not know yet if Mable, steady flight will be at all
According to reh_able mrorma11on, amont: the interceptor
prototypes at 9ran1cnburg, at the time of the Occupation.
possible within the tran,-sonic regime (extending from about
0.8 to 1.2 Mach Number) while there is certainly that beyond
were the following:-One Honen taille,, delta-wing, which had
been dama_ged d(!rmg tests and ~as undergoing repair: another
this tran~-sonic regime. i.1:., within the supersonic regime, ~table.
steady flifht can be predicted.
Honen ta1lle,, Jct-fighter was J.ust ready for it~ first test,.
There was also the latest version of the lippi-;ch-Junker,,·
Two \ample mean, have become known which delay the
dev~lopmem of. the Mc 16.\-C: another advanced Junker,
occurrence of lhe "shock stall" until much higher (but still
sub,onic) flying speed, are attained.·
One is sweep of the
design: an experimental Gotha. and several re;,earch gliders.
,
leading edge of the wing, either a, sweep hack or a, ,weep
Hitler's Last Secret Weapon
forward.
The othe~-a Farnborough _discovery of nearly
The G~rman long-term development of an aeroplane capable
30 years ago, when high top ,peed, of a1r<.erew, were investi­
~f reac_hing truly supersonic ,peed, discarded the gaHurbine
gated-i, the adoption of very thin aerofoil sections.
The
1et engine.
It wa, based on the ram-jct or aerodynamic pro­
latter lend,. as we ~ave pointed out already. straight to aerofoils
puhivc due~ (" Ath_odyd ")-the simplc~t en11ine ever' invented
of low a,pect ratio when, for rea,on, of structural ,tiffness
1 ~e. ram-Jet, a widely d1,cu,,ed invention by the genial Rtnci
a certain wing thickne,, is required.
'
Lorin in 1~1~. had been c~pcrimented with in Germany, notably
ln the discu,sion of the "Stalling Characteristics of Toille,s
hy the Austrian Cugcn Saenger (for whom a special laboratory
Aeroplanes'' (THP AER0PLANr for April 2.5. 1947). it was
had been built hy the German authornie~ in 1938), by Otto
,hown that a_t low soecd,. i.e., duri_ng take-off and landing,
Pabo\t, of Focke-Wulf, _an~ by others.
Following a suuestion
swept-back win1t,s ,uffer from the d1s.1dvanta11e of in,tability
m~de by Al~xander L1pp1sch (formerly known as an eminent
at the ,tall.
W11h pronou_n~ed sw«:ep-back, &wept-back wing,
sa1lplnne des1(tner and resc~rch worker on _tnillcs, aeroplanes).
of normal a~pcct rataos exh1b11 the vice of" ,clf-,talling," due to
prog~e~, had been made wath the combustion of solid fuel in
premature tap stall. It was al'° shown that this vice can be
ram-1ets. Such fuel took the form of ~olid blocks of ~pccinlly
remedied bv reducing the a,r>ect ratio. and a curve based on
r,rcpared coal which lined the walls of the doct. This develop­
exten,av~ wind-tunnel te,ts CT11c ~ER0P~~c for July t I. 1947,
ment ha~ bee~ perfected by the German Research In1titutc­
p. 47, F111_. 8) proved that there 1, a dastmct relation between
for Soarmg Fhaht.
a,r,ect ratio and an11le of sweep-back in this connection.
(To ~ continued.)
NND 927545