Sunday, October 15, 2000

Osprey gets passing grades,
but more testing is urged

By Chuck Vinch
Washington bureau chief

WASHINGTON — Navy evaluators have given the new V-22 Osprey a passing grade for its land-based operational capabilities, but recommended more testing at sea before deciding whether to push the aircraft into full-scale production, Marine Corps officials said Friday.

Chief of Naval Operations Adm. Vernon Clark and other Navy and Marine Corps leaders were briefed Wednesday on the aircraft’s operational evaluation report, which follows almost a year of tests.

The report "moves the tilt-rotor aircraft a major step closer to full-rate production," the Marine Corps said in a statement Friday, although one final hurdle involving ship-based capabilities must be cleared before that decision is made.

But officials said the V-22’s remaining sea-based issue, which involves the process that allows the rotor blades and wings to fold compactly for storage of the aircraft aboard ships, already has been solved.

"Since completion of operational evaluation, the system designed to fold and stow the prop rotors and wings was modified and successfully demonstrated at the V-22 final-assembly facility in Amarillo, Texas," the statement said. "Follow-on evaluation at sea is expected to be completed by Nov. 15."

If those trials are successful, as expected, they will "pave the way for full-rate production and multiyear procurement," the statement said. A final decision to move into full-scale production is expected before the end of the year.

The V-22, built jointly by Bell Helicopter and Boeing, flies like a helicopter for takeoffs and landings and, once airborne, converts to a turboprop plane. The Marine Corps plans to buy 360 aircraft and the Air Force plans to buy 50.

The aircraft is designed to be able to land on a ship in helicopter mode and fold two outboard blades of each rotor inward. In the next step of the wing-and-rotor-folding process, the nacelles of the V-22 are rotated to horizontal cruise mode and the wing then rotates 90 degrees clockwise so it is parallel to the plane’s fuselage.

The march toward full-scale production hit a snag last April when one of the test aircraft crashed during operational testing near Tucson, Ariz., killing all 19 Marines aboard. An investigation concluded that the crash was due to pilot error rather than any mechanical or design failures on the aircraft.

The report said the pilot entered into a descent that was too rapid and too steep, inducing a condition known as "vortex ring state" in which one engine stalled. That pulled the plane over on its back and down to the ground nose-first.

Additionally, the small fleet of V-22 test aircraft was briefly grounded in August after one plane made a precautionary landing in North Carolina, where an inspection found that a coupling on the main drive shaft had come loose.

But aside from the wing-and-rotor-fold issue, the evaluation report concluded that the V-22 "met or exceeded all other key performance parameters" since last November, when operational tests began.

The aircraft was evaluated using field operating forces in a variety of scenarios, including missions from amphibious ships, airfields, remote sites, confined areas and ranges and other test facilities.

The aircraft "proved its overwhelming superiority" to the CH-46E and CH-53D, the aging medium-lift aircraft the Osprey will replace, the report said. In comparison to the CH-46E, the V-22 has twice the speed, five times the range and triple the payload capacity.

Marine Corps officials have remained steadfast in their support for the program. Lt. Gen. Fred McCorkle, director of Marine Corps aviation, said in May that his service’s leadership was "rock solid" in its belief that the aircraft is structurally sound.

"The Osprey is clearly much better, much safer, and more capable than the Vietnam-era aircraft that will replace it," McCorkle said.