By Staff Writer | January 1, 2008
MILITARY | UTILITY
U.S. Marine Corps leaders have been mum on the V-22 since 10 were deployed to Al Asad Air Base in Iraq three months ago, in part because of what they consider a cheap and outdated shot at the Osprey in a major news magazine. But the commandant has shared some info.
Gen. James Conway, meeting with reporters at the Pentagon in early December, said the Bell Helicopter/Boeing MV-22Bs of Marine Medium Tilt-Rotor Sqdn. 263 (VMM-263), the "Thunder Chickens," had begun flying aerial scout missions in support of raids in Al Anbar province.
Raids in the province have become less frequent, he conceded, but added the Ospreys are demonstrating one of their advantages.
"The 22 is very quiet," Conway said. "It’s an added advantage when it comes to getting troops on the ground without hearing a helicopter coming from a couple miles out."
He also said the Thunder Chickens’ aircraft have maintenance rates "about where we would want them to be."
The Osprey’s mission profile "is precisely that of the aircraft it’s replacing" — the Boeing CH-46E and the Sikorsky Aircraft CH-53D. "They’re doing everything those airplanes do, except they’re doing it three times faster."
Stateside, the Naval Air Systems Command ordered flight restrictions on Ospreys following the investigation on an in-flight on one on Nov. 6. Specifically, crews were ordered to turn off the engine air particle separator on their aircraft.
Investigators believe the nacelle fire that prompted the Osprey crew to make an emergency landing in North Carolina was caused by problems with the engine air particle separator. The fire caused about $1 million worth of damage to the aircraft. Bell and Boeing are producing kits to modify the system and eliminate the problem.
The separator is essentially a blower that clears debris out of the air paths to the V-22’s Rolls-Royce AE1107C Liberty engines. When the separator system fails and stops suddenly, however, it can temporarily overload the hydraulic system that drives it. That shock is known to weaken hydraulic lines and lead to cracking and leaks. High-pressure hydraulic dumps into a hot engine nacelle is a known cause of serious fires on the V-22.
The Ospreys in Iraq were modified before they were deployed.