What happened
On November 5, 2003, at approximately 10:44 JST, a Japan Airlines flight, operating a Boeing 747-100B SUD with registration JA8176, was descending toward Naha Airport in Okinawa. The aircraft, carrying 494 passengers and 15 crewmembers, was flying under Instrument Flight Rules (IFR) and descending through 3,000 feet to intercept the final approach course.
Simultaneously, a two-ship formation of McDonnell Douglas F-15C fighters from the US Pacific Air Forces was operating under Visual Flight Rules (VFR) near Kadena Airfield. As the F-15Cs were maneuvering in a landing pattern, they were instructed by Kadena Tower to execute a right turn to break the pattern due to other landing traffic.
As the Boeing 747-100B SUD descended, the flight crew visually identified the F-15Cs. Shortly thereafter, the aircraft's Traffic Alert and Collision Avoidance System (TCAS) issued a Traffic Advisory (TA) followed by a Resolution Advisory (RA) commanding "descend, descend." The crew responded by increasing the rate of descent and reducing engine power. During the maneuver, the F-15Cs passed through the flight path of the airliner. The aircraft reached their closest horizontal proximity approximately 12 nautical miles north of Naha Airport. There were no injuries and no damage to either aircraft.
The investigation
The investigation examined radar recordings, airborne data systems, and interviews with the flight crew of JA8176 and reports from US Forces Japan. Investigators analyzed the flight paths of both the airliner and the F-15C formation to determine the level of risk. The inquiry also looked into the air traffic control instructions issued by Kadena Tower and Okinawa Approach during the period of the incident.