Summary of Navy incident over the Sea of Japan involving EME and radar tracking and about 70 aggressive non-firing passes by unknowns

Tuesday, April 14, 1953

by Brad Sparks

April 14, 1953.  Sea of Japan (at 43°07' N, 135°40' E, about 200 mi E of Vladivostok, USSR).  9:23-11:50 p.m. (Japan time UTC+9).  US Navy Pacific Fleet P2V Neptune [probably P2V-3W electronic ferret ELINT spy] aircraft flying at 9,000 ft [and ~200 mph] course 245° observed 2 bright lights flashing in [Morse?] code letter "D."

Lockheed P2V-3W Airborne Early Warning/ELINT Neptune

The 2 unidentified aircraft paced the P2V from a position [radar-tracked] about 12 miles away to a point 170 NM (~195 mi) along its flight path, at 41°45'N, 132°20'E (heading towards N Korea [along course 242° at approx. 10:15 p.m.]), where 3 additional unidentified aircraft joined.  All unidentified aircraft closed to 3 miles when the P2V descended to 2,000 ft.

P2V continued along [great-circle course, bearing now 240°, additional ~76 mi to approx. 41°12' N, 131°04' E] when at 10:43 p.m. the P2V turned [ESE at 115° initial bearing and away from N Korea and the pursuing UFO's] and flew towards [Niigata] Japan to 39°05'N, 136°33'E [latter point ~160 mi from Niigata Air Base, Japan, 37°57' N, 139°08' E, along ~118° great-circle course], descending to 400 ft above the ocean.

At least 5 more unidentified aircraft joined making a minimum total of 10 UFO's.  Night was extremely dark with ceiling and visibility unlimited.  No recognition features seen [no wings, tails, etc.] on the unidentified aircraft despite 100+ separate aircraft Close Encounters to within 400 ft (except what was interpreted as an occasional jet glow).

From 10:43 p.m. until about 11:50 p.m. the P2V was the target of at least "70 aggressive non-firing passes" or "attacks."  UFO tactics were to have one UFO on the P2V's quarter at about 7 miles away.  The other UFO's made "high speed runs," some from abeam of the P2V but most from astern (behind the P2V) all 70 "attacks" passing under the P2V still flying at 400 feet [but now increasing to ~300 mph near max speed to escape attacks].  At least 10 passes were made by 4 UFO's in formation with runs from astern all passing below the P2V, at 400 ft.

Unidentified aircraft formed a group and departed when the P2V was about 100 NM (115 mi) off Niigata, Japan [thus at about 38°43' N, 137°15' E and about 400 miles from N Korea and Vladivostok].

The P2V was on an ECM mission [ELINT mission] at the time of the interception (and unarmed).  Five "cuts" [ELINT Direction-Finding D/F intercepts] were obtained with at least 3 of these emanating from UFO's confirmed by radar.  Radar from one UFO possibly used to position and control the other UFO's for attacks.

UFO Signal characteristics: frequency 2790 MHz, PRF 500 - 550 Hz (or pulses per second) and PW (pulse width or duration) 1-1.5 microseconds. 

See similar incidents on Jan. 12, 1950, March 14, 1953; also RB-47 case July 17, 1957.

(Sources: Sparks:  Jan Aldrich NARA 1st Marine Air Wing Weekly Combat Summary April 16-23, 1953; McDonald files; BB files)

Duration: 2 hrs 27 mins  ~10 witnesses   ELINT radar emission; visual coded signal; RV

Project 1947