Japanese F-35 disappears over Pacific Ocean

April 9 (UPI) -- A Japanese F-35A stealth fighter jet disappeared from radar while over the Pacific Ocean on Tuesday, prompting defense officials to ground the aircraft model, the Air Self-Defense Force said.

The F-35A disappeared during a training exercise after taking off from Misawa Air Base in northeastern Japan. The pilot, a major in his 40s, was flying with three other aircraft near Aomori prefecture when he lost contact.

Officials are unsure whether the plane crashed and, if it did, whether the pilot was able to eject from the aircraft.

"The cause [of the disappearance] is unknown," Defense Minister Takeshi Iwaya said.

Planes, helicopters and warships were searching the area for signs of the pilot or wreckage.

The Defense Ministry "will put all our efforts to save the life [of the pilot] first," Iwaya said.

He added that military officials have suspended further flights using F-35As. The Japanese air force began using the aircraft in January 2018, and formed its first squadron in March. It has 13 F-35As in its fleet.