The Navy has grounded its test fleet of V-22 Osprey aircraft for about two weeks so workers can replace potentially faulty hydraulic lines, military officials said Friday.
Testing at the Texas factory that assembles the Ospreys found that hydraulic lines were failing more quickly than they should have, said Ward Carroll, a spokesman for the Osprey program. The Navy switched suppliers and will begin replacing the potentially faulty hydraulic lines on Monday, he said.
"This story's about a supply chain that wasn't up to spec," Carroll said.
The grounding comes at a critical time for the $40-billion Osprey program, which has been plagued by safety problems and faces a crucial hearing in May before a Pentagon panel that will recommend whether to keep it. Testing of the helicopter-airplane hybrid resumed last year after being suspended in December 2000 after two fatal crashes.
Carroll said he didn't think the testing suspension would hurt the Osprey's chances of being approved for full production.
Pete Aldridge, the Pentagon's chief of technology and weapons buying, said in November that the new Osprey testing was going well. Aldridge added that he remained skeptical about the Osprey's tilt-rotor technology, which allows the aircraft to take off and land like a helicopter and cruise like an airplane.
The Osprey is frequently mentioned as a possible target for elimination as the Pentagon looks for budget savings. Each Osprey costs about $90 million.
The Marine Corps wants to replace its transport helicopters with Ospreys. The Osprey would be faster and have a longer range than current Marine helicopters. Air Force special operations units also want the Osprey.
A December 2000 crash near Jacksonville, N.C., that killed four Marines was blamed in part on hydraulic lines damaged by rubbing against electrical lines as the aircraft's rotors were tilted. The hydraulic and electrical lines are now separated, Carroll said.
The latest issue with the aircraft's hydraulic lines is unrelated, Carroll said.