Tactical Fighter Training Group F-15 crash

The Tactical Fighter Training Group F-15 crash (Hikō Kyōdōgun F-15 tsuiraku jiko) was a Japan Air Self-Defense Force fighter crash that occurred off the coast of Komatsu, Ishikawa Prefecture, on 31 January 2022 (Reiwa 4).

An F-15DJ fighter belonging to the Tactical Fighter Training Group (the so-called aggressor unit), which had taken off from JASDF Komatsu Air Base to go on a training mission, crashed shortly after take-off, and the 2 crew members were killed in the line of duty. As a result of the investigation, it was presumed that the pilot had fallen into spatial disorientation and crashed, and a report was published stating that there had been no abnormality in the aircraft.

Cause of the accident and countermeasures

The cause of the accident and the presumed state of the accident aircraft described below were derived by the JASDF accident investigation committee after investigating the flight recorder and the airframe.

Cause of the accident

It is presumed that after taking off from Komatsu Air Base, during a climbing turn in cloud, the crew fell into spatial disorientation; as the accident aircraft's right roll increased, it gradually went into a nose-down attitude, and the crew was late in recognising that altitude was dropping rapidly; they noticed the situation just before the crash and performed a recovery manoeuvre, but it was too late, leading to the crash.

As the main factor in the delay in the crew's situational awareness, it is highly likely that they were in a state of spatial disorientation, influenced by the meteorological and sky conditions at the time of the accident and by operations such as changes in attitude and thrust immediately after take-off; in addition, because they were concentrating their attention on radar operations and the like in order to acquire the No. 1 aircraft, it is possible that they did not recognise the accident aircraft's attitude until the recovery manoeuvre was performed.

Presumed state of the accident aircraft

On that day the cloud top (the altitude of the uppermost part of the clouds) was 800 m, and the ceiling (cloud base) was 150 m. For this reason, the formation entered flight in cloud immediately after take-off, and the accident aircraft reported "negative tied on". After that, the crew apparently fell into spatial disorientation, and from about 19 seconds to 11 seconds before the crash, the roll angle gradually increased from the correct angle of 50 degrees right to 81 degrees right, and the nose attitude angle also gradually decreased from the correct angle of 14 degrees up to 1 degree up. As a result, about 11 seconds before the crash, altitude began to decrease (maximum altitude was about 650 m). The accident aircraft continued to descend without the situation being recognised, and 4 seconds before the crash the roll angle was 90 degrees right and the nose attitude angle was 20 degrees down. The accident aircraft passed through the cloud base in that state, and about 2 seconds before the crash the crew apparently recognised the situation and performed a recovery manoeuvre from the unusual attitude. In the recovery manoeuvre, within about 2 seconds the roll angle went from 90 degrees right to 31 degrees right and the nose attitude angle from 25 degrees down to 3 degrees up, an abrupt and rapid manoeuvre imposing a vertical load of 8 G was performed, but it is presumed that the aircraft could not recover and struck the sea surface in that attitude.

Timeline

Unless otherwise stated, all dates are in 2022.