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Saturday, July 28, 2012
Low-level Osprey flights risky: expert
Maneuverability in formation said impaired and autorotation lacking
WASHINGTON — Flying tilt-rotor Ospreys at extremely low altitudes over mountainous areas is far more dangerous than operations planned near the U.S. Futenma base in Okinawa, as the aircraft become more susceptible to air currents that can trigger pilot errors, a U.S. defense expert has warned.
The MV-22 Osprey is incapable of agile movements when its rotors are angled for helicopter flight, and a host of factors can prompt poor maneuvering during such training flights, Rex Rivolo, currently head of technology at a military aircraft-related company in Virginia, said recently.
This risk is especially high when several MV-22s — which take off and land vertically like a chopper — fly in formation because they can be affected by each other's rotor-generated turbulence, Rivolo pointed out.
"The wake of one airplane can upset the other," especially when Ospreys are flying very slowly in formation, said Rivolo, a former chief analyst at the Virginia-based Institute for Defense Analyses.
"There are lots of opportunities for the pilot to make a little mistake. And if you make a mistake in an MV-22, you crash."
However, the United States has no plans to alter the low-altitude Osprey flight training over mainland Japan, Defense Department spokesman George Little told a press briefing Thursday.
"I am not aware of any changes" to the missions, Little said in Washington.
The U.S. Marine Corps plans to conduct such training at locations across Honshu, Shikoku and Kyushu.
Although the corps acknowledges the risk of low-altitude training and imposes a minimum flight distance between MV-22s, Rivolo argues the measure is insufficient.
He also said the aircraft is incapable of autorotation, a helicopter maneuver in which the rotors keep turning and their speed and pitch can be controlled in the event of an engine-out situation that requires an emergency landing — and said that if both its engines fail, an Osprey will simply drop out of the sky, contradicting claims by Tokyo and Washington.
Rivolo accused the U.S. of lying about the Osprey's ability to autorotate, and called on Tokyo and Washington to declare that the aircraft is incapable of such a function. However, he admitted the chances of an official announcement to this effect are slim.
The aircraft are intended to replace the CH-46 helicopters at the Futenma base and Rivolo claimed the Ospreys would be safer than the aging chopper fleet, as long as they engage in normal flight operations.
Despite mounting local opposition, 12 MV-22s were offloaded at U.S. Marines Corps Air Station Iwakuni in Yamaguchi Prefecture earlier in the week, ahead of their planned deployment to the U.S. Futenma base in a residential area of Ginowan on Okinawa Island.
Many municipalities lying under the scheduled flight training routes have expressed extreme safety concerns due to a number of crashes involving the tilt-rotor aircraft, most recently in Florida in June and a fatal accident in Morocco in April, both during training exercises.
On the planned deployment of F-22 stealth fighter jets to U.S. Kadena Air Base, also in Okinawa, Pentagon spokesman Little said the aircraft "will arrive very soon."
"The F-22, we believe, is a very important aircraft in the Asia-Pacific portfolio and in our overall fleet," he said. "The aircraft has been deployed to the region, to other areas of the Asia-Pacific in the past, so it is in some ways natural that they would return to Kadena."
U.S. Defense Secretary Leon Panetta recently approved plans to begin lifting flight restrictions on the F-22 after addressing oxygen-flow problems some pilots had experienced.