(FILES) This file photo taken on October 14, 2018 shows an F-35 fighter aircraft of the Japan Air Self-Defense Force taking part in a military review at the Ground Self-Defence Force's Asaka training ground in Asaka, Saitama prefecture. - A Japanese F-35 stealth fighter jet with one pilot on board disappeared from radar while on a training mission over the Pacific on April 9, 2019 night, the defence ministry said. (Photo by Kazuhiro NOGI / AFP)