Japan has asked the U.S. military to ground its V-22 Osprey aircraft after one crashed into the sea Wednesday in western Japan, killing at least one person onboard, its defense minister said.
The U.S. Air Force, which was operating the hybrid aircraft, says the cause of the mishap is as yet unknown.
"The occurrence of such an accident causes great anxiety to the people of the region … and we are requesting the U.S. side to conduct flights of Ospreys deployed in Japan after these flights are confirmed to be safe," Minoru Kihara said in parliament Thursday.
Japan's Ground Self-Defense Force, which also operates Ospreys, will suspend flights of the aircraft until the circumstances of the incident are clarified, another senior defense ministry official said in parliament.
A spokesperson for the U.S. military forces in Japan declined to immediately comment on the grounding request.
Witnesses said the aircraft's left engine appeared to be on fire as it approached an airport for an emergency landing in clear weather and light winds, media reported.
Developed by Boeing and Bell Helicopter, the V-22 Osprey can fly like both a helicopter and fixed-wing aircraft and is operated by the U.S. Air Force, Marines and Navy, and the Japan Self-Defense Forces.
The deployment of the aircraft in Japan has been controversial, with critics saying it is prone to accidents. The U.S. military and Japan say it is safe.
In August, a U.S. Osprey crashed off the coast of northern Australia while transporting troops during a routine military exercise, killing three U.S. Marines.
Another crash-landed in the ocean off Japan's southern island of Okinawa in December 2016, prompting a temporary U.S. military grounding of the aircraft.
