Air Intelligence Information Report: Ground to Air Missile, Possibly Guided

This document is an Air Intelligence Information Report (IR-1-52) detailing a sighting of an unidentified aerial object by a B-29 navigator on the night of February 24, 1952, over Antung, Korea. The navigator, described as an experienced officer with combat experience, observed a cylindrical, bluish object with a rapidly pulsating gaseous exhaust trail. The object was initially spotted approaching the B-29 from the 7 o'clock position. It performed a series of maneuvers, including a climb at a 45-degree angle, leveling off, and turning toward the B-29 as if to intercept. The object closed on the aircraft at high velocity for approximately 15 seconds before breaking off level flight and descending. The navigator estimated the object came within 3,000 feet of the aircraft and appeared to be the size of an automobile. The B-29 was flying at 22,000 feet at 200 knots. During the incident, the aircraft was illuminated by searchlights, and the crew encountered weak, inaccurate flak. The electronic countermeasures operator reported picking up weak electronic signals for a short duration. Following the report, the incident was referred to the ATIC guided missiles group for evaluation. Preliminary assessments suggested the object might be a subsonic surface-to-air guided missile, possibly similar to the German Schmetterling design. The report notes that while the Soviets were credited with the capability of having such missiles, there had been no prior intelligence confirming their operational use. The document includes internal correspondence between intelligence officers, including Lt. E. J. Ruppelt, discussing the need for further details from the Far East Air Forces (FEAF) to complete the evaluation. The report concludes that the bright blue flame and the object's flight characteristics suggest the use of alcohol and liquid oxygen fuel and a potential electronic guidance system.