Navy Probes Multiple V-22 Surges, Stalls

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InsideDefense.com NewsStand | Christopher J. Castelli | July 17, 2006
In addition to the compressor stalls that recently caused a V-22 Osprey to make an emergency landing in Iceland, other V-22s last week experienced compressor surges that were imperceptible to pilots at the time and officials are investigating whether all of these problems are related.

Two V-22 Ospreys departed July 10 from Goose Bay, Canada, for what was supposed to be a nine-hour, direct flight to Farnborough, England. About halfway through the trip, however, there was an incident that forced one of the V-22s to land in Keflavik, Iceland.

The other V-22, meanwhile, continued on to Farnborough and landed there about four hours later. But it turns out this aircraft's flight was not entirely uneventful. At press time (July 14), Navy V-22 spokesman James Darcy said officials learned from computer data that this V-22 experienced a compressor surge that was imperceptible during the flight.

Also, officials learned that another V-22, which had been in Goose Bay as a backup aircraft, similarly experienced an imperceptible compressor surge during its return flight to New River, NC.

Like a compressor stall, a compressor surge is a disruption of the air flow to the compressor, but it is not as serious, said Darcy. There may be a link between the problems experienced by these various V-22s. At press time, however, Darcy said the investigation is ongoing and would not comment further.

The Osprey that landed in Iceland June 10 had its right engine replaced before flying to Farnborough, where it landed safely July 13 in the early afternoon, said Darcy.

Officials are still investigating what caused the problems that forced the landing in Iceland. Darcy said the first sign of trouble was a compressor stall in the right engine, but he had no details on when this happened. The compressor stall led the right engine to flame out, meaning it stopped providing propulsion, he said. Both of the aircraft's two proprotors continued turning under the power of the remaining engine, he said.

After about “10 seconds,” the pilot was able to relight the engine, said Darcy. Subsequently, however, the same engine experienced another compressor stall, prompting the pilot to land in Iceland at about 2 p.m. Greenwich Mean Time.

Bell Helicopter Textron and Boeing make the Osprey, which can take off and land like a helicopter, but can also fly like a plane. Bell spokesman Bob Leder downplayed the July 10 incident that led to the landing in Iceland, which he called “a common event with turbine-powered aircraft.”

But the Iceland incident was clearly not what V-22 program officials had in mind last month when they issued a press release boasting the Osprey was “writing the book” on long-range deployments. The statement predicted two V-22s would fly July 10 directly from Goose Bay to Farnborough, along with two tankers.

“This will be the first time that an assault support aircraft has ever flown across the Atlantic,” said V-22 program manager Col. Bill Taylor, in the press release.

“Unlike conventional rotary wing aircraft, which must be transported into overseas theaters of operation aboard amphibious shipping or heavy lift transport planes, the V-22 can self-deploy thousands of miles over water to get itself to the fight,” Taylor said in the statement.

Both Ospreys participating in the air show are part of the Marine Corps V-22 squadron based in New River, NC. The V-22 that stopped in Iceland is production model No. 59, known in the squadron as Osprey No. 23, Darcy said. The other aircraft is production model No. 58, known in the squadron as Osprey No. 22.