By / July 16, 2007

Marine Corps officials are tackling a handful of key V-22 Osprey maintenance problems as they prepare to deploy the tiltrotor to Iraq this fall, according to an internal service bulletin obtained by Inside the Navy.

The problems affect various parts of the V-22, including the ice-protection system, the flight-control computer and the air-cycle machine that is important for flying in hot climates. The June bulletin, which sums up discussions held in April, says it is "imperative" for officials to fully understand and resolve the issues.

"Failure to bring these issues to closure quickly will run the risk of significantly impacting aircraft material condition, reducing readiness, increasing supply costs, and degrading the aircraft's ability to support the full scope of operational missions and taskings once in theater," says the bulletin.

Marine Corps spokesman Maj. Eric Dent downplayed the message, noting every Marine aircraft program monitors maintenance items and factors that degrade readiness.

"There are no new issues here, and most have already been discussed publicly in various forums," Dent said. "More importantly, there are mitigation and improvement plans in place for all of these issues."

The V-22 remains on schedule to deploy to Iraq in September, Dent said.

Looking back over a nine-month period, the message says "Block B" V-22s -- the version headed to Iraq -- have been on average 79.3 percent "mission capable" and 62.1 percent "full mission capable." That is better than older "Block A" V-22s, which were on average 47.8 percent "mission capable" and 34.9 percent "full mission capable." But readiness rates for the new V-22s will likely decrease in Iraq, the message notes.

"Based on the historical data available, there is a reason for concern with regard to aircraft readiness and availability as our Block B aircraft begin to reach the flight hour thresholds we have on our Block A aircraft, thresholds we will reach more quickly with the addition of sustained high tempo operations in [Operation Iraqi Freedom]," the message says.

The ice-protection system, the top concern listed, has faced "numerous problems/discrepancies," the message says. The fragility of this system has led to many problems -- with wiring as well as parts that wear out too soon or fail. These problems have been hard to troubleshoot, the message says.

There have also been problems with the flight-control computer and swashplate actuators, which are supposed to help the pilot control rotor movements. Most of the computer problems are likely caused by electrical faults, the bulletin says. The swashplate problems are due to leaky seals, worn out parts and moisture intrusion.

Air-cycle machines in V-22s have often failed because the ingestion of dirt and debris caused bearings to fail prematurely, the bulletin says. There are plans for a new, improved filter that Bell-Boeing would introduce in September 2008, the message says. In the long term, design changes could be needed, too. A team of experts is developing tactics, techniques and procedures to help safeguard the V-22 from dust and sand particles in Iraq, program officials said last month at the Paris Air Show.

The air-cycle machine problem "will negatively impact ability to fly in hot climates, and may negatively impact avionics system cooling creating further readiness degradation," the message says.

If spare parts are available in adequate quantities, this should not be a long-term, major problem, but it would hurt aircraft readiness and availability because V-22s would need to be on the ground to have parts replaced, the message says. "If not properly managed, this could very well be the item that has the greatest potential to adversely affect operational capabilities while deployed forward," the bulletin says.

The message also cites reliability issues with the aircraft's infrared suppressor, problems with the pitch-control-link bearings and difficulties with the Engine Air Particle Separator (EAPS). A possible upgrade for the EAPS, which is designed to filter out dirt and debris, is "at least one year away," the message says.

Overall, the V-22 is doing well, Dent said.

"We have seen continuous improvement in reliability and performance of the aircraft," he said.

The bulletin says there are "adequate solutions" for two separate problems with the nose gear and fuel leaks. Dent said nose-landing-gear modifications have been delivered to the fleet and will be installed prior to deployment, if they have not been already. Also, Dent said a fix for fuel leaks has already been installed on several Marine Corps V-22s and will be on all of the Marine squadron's aircraft prior to deployment.

Bell Helicopter Textron and Boeing make the V-22. Bell spokesman Bob Leder referred questions to program officials. -- Christopher J. Castelli