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Paul Steucke FAA Public Affairs 701 C Street, Box 14 Anch. AK 99513 March 5, 1987 UNCORRELATED RADAR SIGNALS Radar data received by the FAA and used to track Japan Airlines flight 1628 on the night of the November 17, 1986, was retained by FAA. Review of this radar data by FAA experts using identical equipment at the FAA's research technical center in Atlantic City, New Jersey, revealed that the radar system was receiving what is called an "uncorrelated primary and beacon target". This electronic phenomena is not unusual according to Steucke who said, "It is unfortunate that the uncorrelated t…

-- RADAR CELL, 1/4 MILE-- Drawing March 5, UNCORRELATED RADAR SIGNALS An "uncorrelated primary and beacon(secondary) return on a radar screen occurs when the radar energy that is sent up toward the aircraft (primary signal) returns off the surface of the aircraft at a slightly different moment than the beacon (secondary) transponder signal and the two do not match up as being at the same place or same computer radar cell. —_— RADAR CELL --RADAR COMPUTER CELL, 1/4 MILE-- SAME AIRCRAFT (Crossing Cell) SECONDARY RADAR RETURN (Beacon) (Transponder) PRIMARY RADAR RETURN (Skin- Surface) =PRIMARY RAD…

Q Memorandum US. Department of Transportation - Federal Aviation Administration Subject’ INFORMATION: Description of Radar Split Image; Date: FEB 27 1987 AAL-5 Memo of 2/5/87 Reply to From: Manager, Airway Facilities Division, AAL-400 Attn. iol. To: Public Affairs Officer, AAL-5 This letter transmits our analysis of the radar targets associated with JAL flight 1628, on November 17, 1986, and supplements discussions we have had regarding what has been referred to as "split images". We concur with the interpretation provided to you by the Alaskan Region Air Traffic Division. The attached Analysi…

ANALYSIS OF UNCORRELATED PRIMARY AND BEACON TARGETS (JAL-1628, 11/17/86 AKST) Approximately 61 minutes of data was extracted from the EARTS CDR printouts relating to the November 18 incident involving JAL-1628 and the alleged UFO sighting. Review of the data involving this incident did not show any abnormalities that could be associated with any type of target as indicated by the pilot of JAL-1628. Radar returns from the aircraft and surrounding terrain vary with the different segments of the flight, but are considered normal for the area. Returns relating to the incident can be categorized as…