The radar wake of a Japanese F-35A stealth fighter disappeared over the Pacific Ocean about 73nm (135km) east of Misawa air base on 9 April at 19:27 local time.

The Japanese military has commenced a search mission for the aircraft and its single pilot, though the country’s air force offered no details on suspected causes of the disappearance. The Lockheed Martin F-35A was engaging in night-time training with three other F-35A jets, according to The Japan Times.

Japanese F-35A Mt. Fuji

Japanese F-35A near Mount Fuji

F-35 Joint Program Office

The aircraft belonged to Japan’s first operational F-35A fighter squadron, the 302nd Tactical Fighter Squadron, which was stood up on 29 March. The 302nd squadron is stationed at Misawa air base in the northern part of Japan’s main island.

The stealth fighters are replacing the 302nd squadron’s aging third-generation Mitsubishi F-4EJ Kai fighters, which are Japanese-licensed variants of the Vietnam-era McDonnell Douglas F-4 Phantom II. The first aircraft to be assigned to the 302nd Tactical Fighter Squadron was also the second F-35A assembled at Mitsubishi Heavy Industries’ F-35 Final Assembly and Check-Out facility in Nagoya, Japan.

Japan plans to buy 147 Lockheed Martin F-35s, a mix of 105 F-35A conventional take-off and landing variants and 42 F-35B short take-off and vertical landing aircraft.

If Japan’s fighter had crashed it would be the second such major mishap for the F-35 worldwide fleet since the aircraft began flying about 12 years ago. However, it would also be the second major accident in the last eight months. The first crash was that of an F-35B near USMC Air Station Beaufort, South Carolina in September 2018.