On April 7th, a British Aerospace U-125 aircraft, attached to the Japan Air Self-Defence Force’s Hiko Tenkentai Flight Check Squadron, crashed near Kanoya Air Base, Japan. The aircraft departed Iruma at 08:49 for a check flight to Kanoya, and landed at Kanoya at 12:06 after refueling. Following the check, the plane took off at 13:15 and performed the remaining checks of the JAT TACAN. At 14:31, the aircraft initiated an ‘alignment orbit check’ over runway 08R, during which it lost radar contact after an anti-clockwise 6nm arc with an altitude of 3000 feet. The wreckage was discovered on Ontake peak of Mt. Takakuma, approximately 1182 meters (3875 feet) above sea level, on April 7th. The pilot, acting as Pilot Not Flying, and the Flight Officer were responsible for the flight. A GPWS warning was issued 12 seconds before the crash, but it was switched off 2 seconds before, without any avoidance maneuvers. The crash was attributed to continued flight until the crash, resulting from a 6nm arc from the JAT TACAN, at an altitude of 3000 feet. Contributing factors included the pilot’s misidentification of heights, visual obscuration, and inadequate response to the GPWS warning.On April 7th, a British Aerospace U-125 aircraft, attached to the Japan Air Self-Defence Force’s Hiko Tenkentai Flight Check Squadron, crashed near Kanoya Air Base, Japan. The aircraft departed Iruma at 08:49 for a check flight to Kanoya, and landed at Kanoya at 12:06 after refueling. Following the check, the plane took off at 13:15 and performed the remaining checks of the JAT TACAN. At 14:31, the aircraft initiated an ‘alignment orbit check’ over runway 08R, during which it lost radar contact after an anti-clockwise 6nm arc with an altitude of 3000 feet. The wreckage was discovered on Ontake peak of Mt. Takakuma, approximately 1182 meters (3875 feet) above sea level, on April 7th. The pilot, acting as Pilot Not Flying, and the Flight Officer were responsible for the flight. A GPWS warning was issued 12 seconds before the crash, but it was switched off 2 seconds before, without any avoidance maneuvers. The crash was attributed to continued flight until the crash, resulting from a 6nm arc from the JAT TACAN, at an altitude of 3000 feet. Contributing factors included the pilot’s misidentification of heights, visual obscuration, and inadequate response to the GPWS warning.