Monday, October 1, 2007
Military/Utility: Osprey Heads to Iraq
Will the Much-Hyped Tilt-rotor Live Up to Its Publicity?
THE U.S. MARINE CORPS CHOSE TO SEND ITS FIRST OPERATIONAL V-22 Osprey squadron to the tilt-rotor’s combat debut in Iraq this month by ship, reflecting problems with de-icing gear, a shortage of refueling tankers, and a decision to avoid unnecessary risk and wear and tear for a non-urgent deployment.
Marine Medium Tilt-rotor Sqdn. 263, which has been training since March 2006 for the first operational use of the Osprey in the aircraft’s 24-year history, is taking 10 MV-22Bs — the Marine version — to Al Asad air base, a major convoy hub about 95 nm west of Baghdad, for a scheduled seven-month deployment.
VMM-263 is to replace Marine Heavy Helicopter Sqdn. 362 (HMH- 362), whose Sikorsky Aircraft CH-53Ds are home-based in Hawaii. The Marines are buying 360 Ospreys to replace their aging Boeing CH-46 Sea Knight troop transports and CH-53Ds. The U.S. Air Force is buying 50 CV-22 Ospreys for special operations missions.
The Marine version currently costs $69.3 million, according to Naval Air Systems Command figures, or about $110 million if all program costs are averaged into the price. The Air Force version is loaded with special operations gear that raises the flyaway cost to $86 million, according to NavAir.
In Iraq, VMM-263 is to carry troops and cargo and be on standby to recover downed aircraft and personnel. The squadron’s Ospreys also will be equipped with litters to evacuate casualties, a role in which pilots and crew chiefs think the tilt-rotor’s added speed could save lives by getting the wounded to primary care more quickly.
The V-22 tilts wingtip nacelles bearing its two 38-ft-dia rotors and 6,000-shp Rolls-Royce AE1107C Liberty engines upward to take off and land like a helicopter and swivels them forward to fly like an airplane. Under specific circumstances, it is twice as fast and has more than three times the range of the 1960s-vintage CH-46. The Osprey cruises at about 230 kt, compared to the CH-46’s 110. It can fly well above 10,000 ft, if crew and passengers have supplemental oxygen.
The first combat use of the Osprey, which was originally scheduled to enter service in 1991, could go far toward settling a bitter debate since two crashes in 2000 that killed 23 Marines led to re-engineering and re-testing of the helicopter-airplane hybrid. The U.S. Defense Dept. has invested $22 billion in the V-22, which started development in 1983 and first flew in 1989.
Critics contend the Osprey is too fragile and costly for the Marine mission. Some also argue that the tilt-rotor’s side-by-side rotors make it aerodynamically unsound. Osprey pilots and program officials reject those arguments.
The problems with the Osprey’s de-icing system are "a series of little issues." Condensation at altitude has at times intruded into ice-protection electronics and shorted out those devices.
The Marines have touted the Osprey’s ability to "self-deploy," or fly overseas or over other long distances with aerial refueling, and VMM-263 originally was expected to get to Iraq that way. The squadron, based at MCAS New River, N.C., made two transcontinental deployments during its workup for Iraq.
VMM-263 was to fly a route, however, that would have taken it over the North Atlantic with five stops en route to Al Asad. Flying at altitudes over the North Atlantic runs the risk of encountering clouds and temperatures that can lead to icing, even in summer.
Icing marred the self-deployment of two V-22s from Marine Tilt-rotor Test and Evaluation Sqdn. 22 (VMX-22), that flew the Atlantic to appear at the July 2006 Farnborough International Air show in England. Ice ingestion caused compressor stalls in one of the Osprey’s engine and its pilots landed in Iceland as a precaution.
The problems with the Osprey’s de-icing system are "a series of little issues," largely resulting from water seepage, said Marine Col. Matthew Mulhern, V-22 program manager for NavAir.
Condensation at high altitudes intruding into nacelle ice protection control units, master ice protection control boxes and blade de-ice distributors, for example, has at times shorted out those devices, which detect ice and feed electricity to heating elements. The ice protection failures shouldn’t affect Osprey operations in Iraq, but have resulted in all 10 of VMM-263’s Ospreys being rated "Partial Mission Capable" rather than "Full Mission Capable," a sore point for commanders and Marine leaders.
NavAir and the builders of the V-22, Bell Helicopter and Boeing’s helicopter division at Ridley Park, Pa., were working on fixes and modifications, including new ways to seal out water, to solve the problems as VMM-263’s aircraft and crews departed last month for Iraq aboard the amphibious assault ship USS Wasp.
Mulhern said a more important reason for sending VMM-263 by ship was that "it takes about every C-130 (refueling tanker) they’ve got on the East Coast to move 10 Ospreys over there, and those guys are employed. They’re doing other things. We know we can do it. (But) do we stop doing all the C-130 stuff we’re doing already? Evidently there was a ship available, so they made the decision to use it."
Mission analyses indicated VMM-263 would need six to eight KC-130 tankers to self-deploy.
Floating rather than flying the Ospreys to Iraq also was preferred because it saves flight hours and reduces the maintenance necessary before VMM-263 can start flying missions in Iraq, others familiar with the reasons for the decision told Rotor & Wing.
The most vehement critics still contend the tilt-rotor is unstable when flying in helicopter mode. They say the side-by-side placement of its rotors makes it extremely vulnerable to vortex ring state, in which a rotor that descends too quickly into its own downwash can lose lift.
The April 8, 2000, crash during operational testing at Marana, Ariz., in which the crew of four and 15 Marines riding in back were killed, was blamed on vortex ring state. An investigation said the condition was induced when the pilot descended more three times as fast as the recommended limit of 800 fpm at less than 40 kt airspeed.
Osprey pilots and Bell-Boeing and NavAir officials say flights tests after the 2000 crashes showed that the V-22 is harder to put into vortex ring state than most helicopters.
Tests also showed that an Osprey pilot can fly out of vortex ring state simply by tilting the rotors forward, given sufficient warning and altitude. NavAir added a vortex ring state warning tone and callout as well as a warning light to the Osprey following those tests.
The Ospreys of the five squadrons flying — three operational ones, a training unit and the VMX-22 test squadron — have logged more than 26,000 flight hours since May 2002, when the V-22 returned to flight after being grounded 17 months following the crashes of 2000.
Pilots in VMM-263 and others who work on the Osprey say they are unworried about the tilt-rotor’s aerodynamics. Of greater concern is how difficult it may be to maintain the V-22 in Iraq’s punishing climate of searing heat and fine sand, which tends to wear out rotor blades and engines rapidly.
Bell-Boeing is sending 14 civilian technicians to Iraq with VMM-263 to help maintain its Ospreys and Rolls-Royce is sending two representatives.
The contractors also have made a special effort to ensure that adequate supplies of spare parts reach the squadron at Al Asad, and the Marines gave VMM-263 first call on parts and personnel within the Corps’ V-22 fleet prior to their mid-September departure.
The ice protection system failures were among issues addressed in a June message to the fleet from the 2nd Marine Air Wing’s Aviation Logistics Dept. on "high-profile maintenance issues" and their potential impact on operations, which caused a stir when leaked to the press. The most worrisome issues, according to the memo, were:
The ice protection system failures.
High failure rates in the air cycle machine, which cools the cabin and avionics, "due to debris and dirt ingestion contributing to premature failure of bearings."
Vibration-induced cracks in panels that cover the infrared suppressors on the Osprey’s engines.
Fuel system leaks.
Nose landing gear failures.
Marine Corps headquarters issued a statement following reports of the memo in which it said there were "no new issues here" and that there were "mitigation and improvement plans in place for all these issues."
A team of Bell-Boeing technicians was at New River in late summer working seven days a week to make modifications to VMM-263’s Ospreys to fix the various problems discussed in the 2nd MAW memo.
"There are no surprises in there," Mulhern said.
According to NavAir, the maintenance issues caused no gaps in the Osprey’s ability to perform during VMM-263’s deployment for training in late May and early June to MCAS Yuma, Ariz.. It was there that the squadron practiced desert flying and took part in Desert Talon combat exercises.
During Desert Talon, VMM-263 was reported to have completed all of its 72 scheduled sorties and flew 631 hours during the deployment.
Some critics contend the V-22, which unlike the CH-46 is largely made from composites and is a fly-by-wire aircraft, will be more vulnerable to ground fire in Iraq than helicopters, several of which have been lost to insurgent fire in Iraq. V-22 pilots and others say the Osprey should be less vulnerable because of its speed and altitude. Maj. Gen. Kenneth Glueck, 2nd Marine Air Wing commander, said the Osprey should be far harder for insurgents to hit than helicopters when en route to landing zones because it will fly higher and faster. The V-22 may be a few seconds slower landing than a CH-46, but is faster getting into a zone than a CH-53, Glueck added.
Fighter-bombers and helicopter gunships will provide escort protection for the Ospreys if they need to land in zones where threats have been detected, Glueck said. The Marines also have installed a 7.62-mm M240G machine-gun on the Osprey’s back ramp for self-protection.