There have been four fatal Osprey crashes in the past two years ... Japan does not intend to conduct its own probe or ask the U.S. to do further investigation because the two sides have shared ...

The V-22 Osprey is a troop transport with a helicopter's versatility and a turboprop's speed. But the V-22 has crashed several times since becoming operational in 2007, killing over 50 people.

There have been four fatal Osprey crashes in the past two years ... Japan does not intend to conduct its own probe or ask the U.S. to do further investigation because the two sides have shared ...