Japanese F-35 fighter (image: CTV News)

The Japanese F-35A stealth jet, which is missing since April 9 was involved in seven emergency landing incidents prior to the crash along with four other F-35s out of 13 in service with the Japanese Self Defence Force (JSDF).

The first accident took place on April 9 when one of the fighters crashed into the Pacific during a routine anti-fighter combat training with three other F-35A jets. The Air Self-Defense Force’s (ASDF’s) radar lost track of the jet when it was about 135 km east of Misawa Air Base in the prefecture. The ASDF had formed the Misawa-based air squadron comprising the 13 F-35As on March 26.

The jet was involved in two emergency landings prior to the April 9 crash, Ministry of Defense revealed on April 16, according to a report by Hiroshi Maetani.

According to some reports, the crashed jet had issues with its cooling and navigation systems during the two occasions when it returned to the base unplanned on June 20, 2017 and August 8, 2018 respectively.

The emergency landings took place between June 2017 and January 2019 during flight tests and drills. The fighters returned to the bases after issues with systems relating to fuel, hydraulics and other parts were reported. Excluding one case of an error by the aircraft's monitoring systems, the remaining six saw the fighters inspected and parts replaced before they were confirmed safe to fly.

Out of the five jets that made emergency landings, four of them inclusive of the crashed fighter, were assembled in Japan by Mitsubishi Heavy Industries, Ltd. The other aircraft was built and assembled in the United States (US), the report stated further.

Japan has plans to procure a total of 147 F-35 fighter jets, 105 of which are expected to be F-35As for the ASDF.

Minister of Defense Takeshi Iwaya addressed the need to investigate the cause of the crash at an April 16 press conference. The minister has planned to discuss the issue at a Japan-US Security Consultative Committee "two-plus-two" meeting set to take place in Washington on April 19.

"The technology on board the F-35 is highly classified. With cooperation from the US, we would like to take the initiative in thoroughly investigating the causes while gaining cooperation from the US," he said.