PROJECT BLUE BOOK

——-— =

PROJECT 10073 RECORD CARD

—-

Ty. pate 2. LOCATION ‘12. CONCLUSIONS

@) pal ate aeac

! bry ra) ; 0 Probo Balloon

__ 19 February 1958 Hokkaido, Japan 5 Possible Balloon

| 3. DATE-TIME GRouP 4. TYPE OF OBSERVATION
O Was Aircroft

1 Lees! DGround- Vi sual %KSround-Rodor O Probobly Aircraft

| GMT 19/00592Z 0 Air Vi suol O Air-Intercept Radar GO Possibly Aircroft

|S: PHOTOS &. SOURCE 0 Was Astronomical

oY O Probebly Astronomice

ot ee Sketch Mi litary 0 Possibly Astronomical

"7. LENGTH OF OBSERVATION 3. NUMBER OF OBJECTS | 9. COURSE 4X Other_Explosion  _

| DO Insufficient Date for Evaluation
Q Unknown

| 2 hours _ one stationary

i 1). COMMENTS

(10, BRIEF SUMMARY OF SIGHTING

|; Radar report from Sea of Japan area,

| Return daveloped rapidly to 2 dense

| Cloud that expanded to cover an arga
aporoximately 65 miles long and rose
rrom an altitude of 3,000 ft to 46,
OOUft, Return Similar to weather
return except for speedof development.
Five aircraft in area all turned towaf

| the return and proceeded to the genera

/ area, Return resembled explosion of

larg? munitions ship exploding,

Rapid development and a/c reaction
rule out weather p&esnomena and
equipment malfunction, Explosion
possibis cause correlated with
IR i8860-58 as explosion. c detect
3

by fishermen, Also seismic detec
tion of nuclear explosion report
from Matsushiro,

——— —

ATIC FORM 329 (PKV 26 SEP 52)

= Pee - —

Set WA, Card 5/3 USSR Pe eect ",

23469
IR-100~58

~ Rpt #1

UNCLASSIF ED

cys with incl 1 & 2, 1 cy each

3 Theiss

Overlay

Scope presentation
Source's original report,

424 Annotation: 3 Incls Received

' May 26, 1958

DOWNGRADED AT 2 YEAR INTERVAIS;
DECLASBIPIBD APTER 12 YEARS

Do bik 5Le0.10

|
|

UNCLASSIFIED:

Classification Cancelled?
Aged to

(orc
Auth

Ry

Pas

oe. |
9,

, fr
a foun.
+ HPs tg

Delo: Fabruary 19, 1958
Set 1/1, Card 1/3 Eval: B~2
Ref: Nore Given
info Spee: DE/MT/snh =~
Distr: ZEL/Ela-6 cys/4Eld-3 cys/4F2/43/saLg/

Entire Document y
While conducting surveillance of Russian aircraft/on 19 Feb 58 at 00592,

age iets Ss
i

seater uss UNCLASSIFIED QQRBGIOIRIID, ont. ox ee sc yyy
Subject: Unusual Radar Sighting Associated MC #: 23469 j Key. |
With Russian Aircraft Activity AF #: 1165758 VA LW
Source: Det #45, 613th AC&W Sqdn APO 181, Rpt #: IR-1i00-58 2
San Francisco, California Agency: Ha 39th Air Div Moawa AB
Preparing Officer: ROBERT C. LAIDLAW, Capt, Japan }
USAF D.Ro: February 27, 1968

}

—-— =

operations personnel of AC&W Site #45 at Asoiwayama (GEOREF XJGP 3020) (Hokkaido)
Japan observed the ee development of an unusual radar return on FPS. (HRT)
height finding radar“(see Incl 1). The radar return was from the area of 40°
30 min north, latitude, 137°30 min east longatude (in GEOREF Grid XJCQ) over the
Sea of Japan approximately 80 nautical miles off the Russian Coast (Meritime).

“ne return developed to a dense cloud that expanded to cover an area approximatei |
Classification Cancelled
‘Apap AT? year mereevars: — UNC] Avy, (oi ops Huy
tthe a Pg a : : ' r. iy ed YEARS. aa IDO! j = P Aust} ~" al “a : fos Le ei
bi D3: > Ce} e ANREP rom mead By JTL PT (CLF,
” a + 4 » “7 ™ ° w / , »

tS eae

fh

ee ae

i s

Set ii, Card oALINCLASS Ek. iO! PENS TP URE oa 23469 | y
Rpt + IR-:100-58 ILA
65 milés long from 44°10 min north 137°10 min east to 45°30 min north 137°40 min /ADl,
east and approximately 25 miles across which rose from an altitude of 3,000 feet
to a final altitude of 46,000 feet: The return was similar to a weather return
except. for the: speed of its development. appeared at 0059Z and Gissipated at
0300Z.- All five Russian aircraft tracks in the area proceeded to the general
vicinity of this phenomenon.'3 Observers were unable to describe the return and
associated Russian reaction in terms of any previous experience. Observers stated
that it most nearly resembled a very large explosion such as that of a very large
ammunition ship. A weak low pressure area was located in the Sea of Japan approxi
mately 41° north latitude. Winds at Site at 20,000 feet were from 260° at 50 knots,
weather was CAVU. The above data was furnished by Capt Henry Kolb, Det 45 Operations
Officer, who wi ed event along with lst Lt. Thomas Y. Cole, Ass't Operations
Officer and Mr. Tech Rep. on GEFPS-6,. 30DO0IComments Rapidity of
development plus apparent Russian aircraft reaction would appear to rule out a natural
weather phenomenon or a radar malfunction. Veracity of witnesses is not questioned.
No intelligence personnel are assigned at Radar Sites. Site 45 had no radar scope
camera so a’sketch of scope face was substituted. This report delayed due to late
reciept in this Hq (26 Feb 58) and need for preparation of report on reproducable
AF Form 112. .

, ec Classification Cancelled
DA tens ee IFIED (or changed tows; )
Wie eo AP 2 YES Dwreryare UNCLASS Au th Loess od, USAE
Ses es ; f

Psy ; - 4 . . to

en nT OO NETEE
how < ee we MS pee: RS LD OTT Sc ORE a FA STM = ;
Pa hint
Set 1/1, Gard 2/3 Japan/USSR MC gf: None 3
Rpt #: IR-1886-58

600L4th AISS, visited Noboru ITO, Chief of the Aviation Administration Section
and Toru SAHARA, Chisf of the No. 2 Security Section, MARITIME SAFETY BOARD
(MSA) for information on an alleged explosion off the SIESXIAN coas* on 19
Pabruary 1958.

2. Recently, three unknown luminous sightings were made off the coast
of HOXXAIDO by fishermen and reported to MSA. MSA has recorded-thse inci-
dants ‘but will ‘net investigate the matter further. In eacr instance the
sishting wasmade at nicht. There is ne report indicatine en explosion off
she coast of SIBERIA on 19 February 1956.

3. &t 1230 hours (JST} on 31 Octoder 1957 fistermen cbhserved a pillar
of flame 100 m high, 1500 = west of BMEETSU (AL43N/1L14E5) for approximately
15 minutes. The color changed from red to blue then disavregred.

Z. &t 2034 hours (JST) on 1 March 1952 fishermen chserved a luminous
oedy that disavpeared after i0 minutes at an altitude cf arproximateliy 2,000 m
in the direction of NOPSUETO POINT TA L244N/115253) on_KUNASEIRI ISLAND: Tt
solor was net determined. At 2103 hours (JST) on the same day, a luminous
rody was cbserved rising. gradually for about 20 minutes then disacrearing near
CAPADNAYA (ONNERUSU) (4345N/115268). The color was not certainly identified,

sut was not red or crean.

<n mentee pe NI RL LILLE AL IDOLE LO ELOY LL LLL IT

7

. ‘
1 ow . °.

—_ ~ ~
‘

$33 1/1, Card 3/3 Japan/USSR MC #1 None

Rot #: Itissé—sa oo
COMMENTS.OF THE PREPARING OFFICER:

v
At apcroximately 0959 hours (JST) on 19 "ebruary 1958 an unimowm
ite chenemenal? belie ved to heave been an explosion, was detacted at 4£50N/137308
av a US radar site in JAPAN. The phencmena lasted approximately two hours.
This office checksd with the Metecrolozical Agency for barcratric or seismic
Gata on the premise that ean explosion was detonated. I+ was learned that
vnere ware no barometric or Seisnic changes indicative of an explosion at the
above time. Negative infcrmation was alsc obtaired from the Maritine ang
4ir Staff? Offices of the Defense &cancy.

o/ Officials of the “etecrclogical Agency stataa what eny berometric
changa~~culd be dstacted at weather stations in JAPAN, The geisni- ag taction ©
oF a muclear explosinn at the MATSUSEIRO SBISMCLOSICAL CESSRVATCRY 1s believed
%O Rave been instizated fren this search. (Rerer to 600ith AISS, IR LEE5=58
“or seismic dstecticn of USSR

> oe mS

nuclear explosion.)

May 20, 1958