April 10 (UPI) -- Japanese authorities said Wednesday they've found some wreckage from an F-35 stealth fighter jet that disappeared this week.
The plane was found in the Pacific Ocean hours after it went missing Tuesday, officials said. The Japanese pilot is still missing.
Authorities said part of the tail was found about 80 miles offshore from the Air Self-Defense Force's Misawa Air Base in Aomore.
The F-35 was flying in a formation with three other aircraft when it crashed about 85 miles off shore. The pilot had logged 3,200 hours of flight time, including 60 hours on the F-35. He has not yet been identified.
Just before the crash, the pilot told ground controllers he would break away from the exercise. The U.S. Navy is assisting with the search with patrol aircraft and a missile destroyer.
The Japanese have suspended all F-35A flights at Misawa Air Base until further notice.
The crash raises questions about the safety of the most advanced fighter ever built. More than 300 F-35s have so far been delivered worldwide. Tuesday's is the second to crash -- after a U.S. Marine Corps jet crashed in South Carolina last September. That crash temporarily grounded the F-35.
Peter Layton, a former Australian Air Force officer and analyst at Griffith Asia Institute, said the problem could lie with the Japanese assembly line.
"There are several hundred F-35s flying, suggesting a local not fleet-wide problem," Layton said. "The pilot appears to have thought he was in command and not in imminent danger."
The plane that crashed was an F-35A -- one of three variants offered by Lockheed Martin.