September 26, 2012
While acknowledging the necessity of an autorotation capability in an emergency situation, the Defense Ministry continues to proclaim the safety of MV22 Osprey although it lacks the capability.
Autorotation capability is essential for a safe landing of rotorcraft if an inflight shut-down of all engines occurs.
The ministry in August 2007 in its report, which verifies the safety of the U.S. Marine Corps Futenma Air Station in Okinawa, explained that the major and typical cause of aircraft accidents is engine shut-down and that under such a circumstance, autorotation capability is effective in enabling a safe landing. Then, the report emphasized the safety of the Futenma base by stating that all USMC military helicopters at the base can land by autorotation in an emergency.
However, amid mounting public concern that the MV22 tilt-roar aircraft are scheduled to be deployed to the Futenma base without the autorotation capability, the ministry recently announced that it is hard to envisage a situation which requires the aircraft to perform an autorotation landing.
In a document released on September 19 by the defense ministry as a reference to the government’s “declaration” of Osprey safety, the ministry claims that a situation under which the Osprey has to fly in autorotation mode will occur only once in every 10 billion flight hours. The document also states that an aircraft with 100,000 flight hours never experienced a situation in which both aircraft’s two engines simultaneously became inoperative.
The most frequent cause of past Osprey accidents, however, is engine failure.
Regarding a crash of a U.S. Air Force CV22 Osprey in Afghanistan in 2010, it has been pointed out that the cause was insufficient power output from one or both of its engines.
Akahata warns that there is no guarantee that the Osprey engines would always work properly during their flights after the deployment.
Autorotation capability is essential for a safe landing of rotorcraft if an inflight shut-down of all engines occurs.
The ministry in August 2007 in its report, which verifies the safety of the U.S. Marine Corps Futenma Air Station in Okinawa, explained that the major and typical cause of aircraft accidents is engine shut-down and that under such a circumstance, autorotation capability is effective in enabling a safe landing. Then, the report emphasized the safety of the Futenma base by stating that all USMC military helicopters at the base can land by autorotation in an emergency.
However, amid mounting public concern that the MV22 tilt-roar aircraft are scheduled to be deployed to the Futenma base without the autorotation capability, the ministry recently announced that it is hard to envisage a situation which requires the aircraft to perform an autorotation landing.
In a document released on September 19 by the defense ministry as a reference to the government’s “declaration” of Osprey safety, the ministry claims that a situation under which the Osprey has to fly in autorotation mode will occur only once in every 10 billion flight hours. The document also states that an aircraft with 100,000 flight hours never experienced a situation in which both aircraft’s two engines simultaneously became inoperative.
The most frequent cause of past Osprey accidents, however, is engine failure.
Regarding a crash of a U.S. Air Force CV22 Osprey in Afghanistan in 2010, it has been pointed out that the cause was insufficient power output from one or both of its engines.
Akahata warns that there is no guarantee that the Osprey engines would always work properly during their flights after the deployment.
