Monday, August 3, 2009

V-22 OSPREY COMMENTS (Continued) . . .

"Meanwhile, Marine Generals struggle to explain the dozens of missing V-22s to a congressional committee. In March 2009, the Marine Corps announced that all 73 of its MV-22s were grounded for inspection after several aircraft were found with loose bolts. However, Congress has funded 150 V-22s for the Marines through FY2009 (not including CV-22s for the Air Force) plus another 6 V-22s as part of supplemental funding. Around a dozen V-22s used in development have been retired or crashed, and only half of the 30 V-22s funded for FY2009 were delivered as of March. This leaves four dozen V-22s missing, and that's a big gap to explain away.

"There are no longer V-22s in Iraq as the 12 based there have returned home - by ship. As the 8000-man 2nd Marine Brigade deploys to Afghanistan this month, none of the Corps' 140+ new MV-22s will go. The Corps was forced to mobilize a reserve squadron with 25-year old CH-53E helicopters to support them. It also spent millions of dollars to re-engine a squadron of 40-year old CH-53Ds to support that deployment, helicopters that were scheduled to be scrapped in 2006. The CH-53E that has a greater range than the V-22 and can also air refuel and autorotate and carries three times the payload capacity of the V-22.

"Unlike helicopters with blades folded, a V-22 must be unfolded to work on its engines. During evaluations, it was demonstrated that a V-22 can unfold in the center of the hangar deck of an LHA/LHD -- big flattop amphibious ship. However, there is clearance for just one V-22 to unfold, and this blocks the movement of other aircraft within the hangar.

"The only alternative is to perform maintenance topside. That restricts flight operations and subjects maintainers to the weather. There can be no work in very cold weather, rain, or high winds, and maintainers must haul all their equipment and parts topside. Working at night is possible, but only if the tactical situation permits the ship to light up like a Christmas tree.

"V-22s can pivot their wings for storage on ship. This has not been necessary at airbases, but during a typical 6-month shipboard deployment this may be required a hundred times. Each fold imparts stress on the V-22's lightweight titanium hydraulic lines. These become brittle below 50F and may crack. This may be why VMM-266 had trouble in November of last year as it trained on ship as part of the 26th MEU. A CH-46E squadron deployed in its place.

"As a result, folding up V-22s has been avoided ashore. The extent of this problem is unknown, but it would cost nothing to test. On a cool morning, have a V-22 fold up and unfold 100 times in a row, then start her up and see what happens. That simple test alone could doom the V-22 program.

"According to the Osprey community newsletter "Osprey Nation", hydraulic leaks have caused engine fires that ruined three V-22s thus far. Since the V-22's hydraulic lines run along each wing and within the engine nacelles, they are stressed whenever the tiltrotor tilts, whenever the flexible wings flex, whenever the rotors are up and pummel the wings causing extreme vibration, and whenever the V-22 folds and unfolds.

"A conference was recently held on possible solutions. Routing the hydraulic lines outside the engine nacelle was debated. This would prevent fires and allow easy inspection, but would expose them to damage from objects whipped up by the V-22's intense downwash. Engineers preferred the second option of using electric motors. It would take years to develop and test an electrical system, and V-22 production would end before that became available.

"The V-22 was canceled in 1992 after DoD engineers concluded that the tiltrotor concept is flawed. It is possible to build an airplane whose engines can tilt to take-off and land like a helicopter, but the compromise design is so heavy and inefficient that very little payload can be carried. In 1992, Navy Secretary Sean O’Keefe told the House Armed Services Committee: "The V-22 cannot be built to meet the requirements specified. It’s an engineering impossibility."

"After the V-22 was resurrected for political reasons, Bell-Boeing engineers went to work to shed weight. The nose gun and NBC protection system were dropped. The strong kevlar flooring was removed. The fuselage was made 25% smaller than the CH-46E, even though it was expected to carry even more Marines. Components were left off until after test evaluations, like the hoist, deicers, and anti-missile flares. One crewman was deleted. These have been added back recently so payload was cut in half. The V-22 is now several thousand pounds above the "guaranteed empty weight" specified in its contract.

"The V-22 was designed with many more composite parts that any other aircraft in the U.S. military. According to a 2005 Rand study these parts are lighter, but they are far more expensive, more difficult to replace, and nearly impossible to repair. It is not uncommon for trucks or forklifts to bump into a transport aircraft and make a big hole. Bullets and other weapons easily punch holes into assault aircraft. With aluminum, a Marine simply patches it and pounds it into shape. This can't be done with composites because the skin provides some of the fuselage strength. The new big Airbus jetliner has a composite upper body, but uses heavier aluminum for the lower body because they worry that a minor ramp accident could cause millions of dollars in damage to a composite section and require depot-level work to repair.

"The V-22's fuel tanks, fuselage, and passenger seats were so light that they failed testing. New heavier fuel tanks and seats have since been added. However, the fuselage is too fragile and does not meet Navy crash standards unless it lands on a runway like an airplane so it can shed its engines before impact. This fuselage has proven fragile, which is one reason dozens of fairly new V-22s have been retired, although they are officially listed as "preserved."

"1,541 pounds shaved off the original V-22 design weakened the aircraft. After a couple years of service, the lightweight composite body and parts begin to fail. Repairs become too frequent or impossible because of cracks or parts that don't fit after hours of stress and vibration cause minor deformations. As a result, the aircraft is pushed into a hangar and unofficially retired. Proper mishap reports are never filed, and the aircraft is secretly hidden in a hangar. Damage of more that $1 million dollars requires a Class A mishap report and an independent JAG investigation. Nevertheless, no reports were filed as dozens of nearly new V-22's were damaged beyond repair.

"When its engines are in the helicopter mode, its hot jet engine exhaust can ignite dry brush. This has rarely happened as V-22 have been restricted to hard surfaces, or an occasional landing on a bare or green, grassy LZ.

"This incident sounds like a minor crash during a take-off attempt from a swampy area that was caused by tires stuck in mud. The V-22 is twice as heavy as the CH-46E (pictured), so it is much more likely to become stuck in mud at an LZ. A helicopter rescue crewman with many years of experience in Vietnam with the big, wheeled HH-53A said they learned it was best to conduct hover pick-ups to avoid this. If landing was required, a crewman would always jump out and test the soil, because getting stuck in hostile territory may be fatal. Igniting the LZ may also be fatal to Marine infantrymen.

"Marine Corps Brig. Gen. James F. Amos once stated: "I think the V-22 probably is high maintenance at this point. I think -- but make sure you understand one thing. Any new airframe at this point or any new system is going to be high maintenance. And why would that be? Because first of all, there is the real lack of experience in maintaining this."

"The General made that statement about the V-22's poor mission capable rate in 2000, so its ridiculous to use the same excuse nine years later. The V-22 first flew in 1989 and went into production in 1997; it is not new. The V-22 program is older than the C-17 program, and C-17s have mission capable rates above 85% and none have been retired or "preserved." Back in 2001, everyone thought that Brig. Gen. Amos would be forced to retire after he was caught telling lies about V-22 readiness and conspiring to hide V-22 failures from DoD leaders. The Inspector General even seized his computer."

Thanks for doing the homework here, Tom. - S.L.

1 comment:

  1. My pleasure. It's been on my "US military pet peeve" list for years. They cancel F-22 orders and order more birds that have broken wings that never should have been built once the prototypes proved to really suck, and then the vortex ring state problems causing them to occasionally flip on their back and crash, especially while taking off and landing, killing a load of Marines, and they still are buying more???


    The fundamental flaw with the V-22 is that its tiltrotor design can cause a wing induced rotor stall. This is unique to tiltrotors and the cause of what the V-22 program calls "vortex ring state". As a tiltrotor descends vertically, each wing pushes the airflow away from half its rotor. The faster it descends, the greater the vacuum the wings create resulting in less lift. As the pilots maneuver a V-22, they may shift the airflow causing one rotor to lose so much lift that it literally falls and flips the aircraft over.

    This is what occurred to the V-22 during the April 2000 crash. The JAG investigation concluded the pilots erred by descending too fast. However, it's likely the pilots could not slow their descent even by applying full power. This probably surprised the pilots because they were carrying 15 combat-equipped Marines, or about 4000 lbs more weight than during testing...This happened to the Corps' most experienced V-22 pilots during the April 2000 crash. How many times will it happen to younger pilots who must fly in formations, in bad weather, and may be distracted by radio chatter and even anti-aircraft fire? A helicopter cannot flip over from a minor pilot error. All four V-22 crashes were the result of a total loss of control which led to the complete destruction of the aircraft. This fundamental problem makes the V-22 unsafe to fly, especially for use as an assault transport. V-22 pilots have developed a technique to regain control should a V-22 begin to roll over. A change in the nacelle angles of as little as 15 degrees is enough to recover and regain power, however, the aircraft must be at least 2000 feet off the deck to allow time to regain control. This will be of no use to V-22s approaching a landing zone, especially if they fly below 1000 feet the entire mission to avoid anti-aircraft systems.

    This also explains why the program has avoided lifting heavy objects externally. Ideally, the V-22 makes a "non-hover landing" where it glides onto a hard surface for a rolling stop to utilize the lift from its wings and to keep solid airflow under its rotors. However, external cargo must be set down vertically. As a V-22 descends with external cargo, the wings begin to disrupt airflow and reduce performance. A V-22 carrying near its maximum load and descending vertically can easily lose enough lift to plunge to the ground. As a result, many experts have concluded that a "tiltwing" is much better since the wing also tilts to avoid wing induced airflow disruptions. This is also why Boeing has no plans for a commercial tiltrotor and is working on a new VTOL canard wing design where the entire wing can also spin like a big helicopter blade. Meanwhile, the V-22 is stuck with dangerous and poor performing tiltrotors.

    V-22 Lift Performance is Dismal

    Empty Weight lbs, Payload, Vertical lbs. lifting, and, Unit Cost in millions-respectively:

    CH-46E 15,537 10,000 NA
    V-22 33,531 9,000 or less $120
    CH-53E 33,226 32,000 $21 SLEP*
    MH-60S 11,516 9,000 $25

    Which would you pick? Get me a US Navy MH-60S, please. Fit the Osprey's with radio controls like predators and use them as target drones for air to air gunnery practice and stick one in a USMC museum painted with giant letters, "stupidest thing we ever invested in, worse than Chauchats we bought in WW I".