Hong Kong(CNN) Search efforts may be closing in on the wreckage of a Japanese F-35 stealth fighter that crashed into the Pacific Ocean two weeks ago, perplexing investigators and raising questions about the reliability of world's most-advanced warplane.
"We have a pretty good idea where it is," a senior US Navy official told CNN this week, adding that the search area was looking at depths around 1,500 feet (450 meters), far shallower than the 5,000 feet (1,500 meters) that had been speculated, and a depth that would make recovery operations much easier.
The US-designed F-35 is considered to be the best stealth jet technology in operation. It's sudden and unexplained disappearance from radar just minutes into a training flight over the Pacific has raised concerns that China or Russia could try to get to access to the wreckage, though both US and Japanese officials have dismissed the idea.
In response to a question regarding the security of the wreckage during a visit to Washington last week, Japanese Defense Minister Takeshi Iwaya said the country's naval forces were keeping close watch on the search area.
On Tuesday, Iwaya announced plans to dispatch a civilian deep-sea research vessel to the search area east of the northern tip of the Japanese main island of Honshu.
The ship, which the Japan Agency for Marine-Earth Science and Technology calls "the world's most advanced research vessel," carries a remotely operated submarine and equipment to grab samples from the ocean floor.
Iwaya also said the US had chartered a private ship equipped with cranes able to work in deep water to join the effort.
The lost jet went missing while on a training mission from Misawa Air Base in northern Japan on April 9.
The pilot, Maj. Akinori Hosomi, a 41-year-old with 3,200 hours of flight experience, signaled to his squadron mates that he'd need to abort the training mission they were on before his craft disappeared from radar.
Pieces of the planes tail fins were recovered from the sea, but the search continues for the pilot and the bulk of the aircraft.
Japan grounded the other 12 active F-35s in its fleet after the crash.
With 147 of the $100-million-plus F-35s on order, Japan plans for the planes to be the mainstay of its air forces for decades to come, and officials have said since the crash that their faith in the program has not wavered.
The United States has hundreds of the jets in its fleets and on order.
The Pentagon said its F-35 operations were unaffected by the crash. "The US, and all F-35 partners, remain fully committed to protecting all F-35 capabilities and technology," acting Defense Department spokesman Charles Summers said last week.
"The department has full faith and confidence in the F-35 program. All 276 US F-35's continue to fly."