The Army grounded its fleet of CH47D Boeing Vertol Chinook helicopters yesterday after a transmission bearing failure caused the destruction of a taxiing Chinook in Honduras.
Lt. Col. Miguel Monteverde, an Army spokesman, said the April 21 incident occurred as the Chinook, primarily a cargo carrier, was taxiing to a refueling point. The bearing failure caused one of the Chinook's twin main rotors to stop turning. Rotor blades mesh, and when one stops the other hits it.
The Chinook "kind of chewed itself up," Monteverde said. Two injuries were reported.
The grounding order affects only the CH47D, the newest model, of which the Army now has 62. It also has about 400 earlier models, the CH47A, CH47B and CH47C.
Monteverde said that a preliminary investigation has indicated "a heat temper problem with the bearing" and that the bearings will have to be replaced.
"We have not had any problems with the Delta model," he said. "But rather than wait for another Mannheim, we set them on the ground." He was referring to the 1982 crash of a CH47C in Mannheim, West Germany, that killed 46 people. Bearing failure -- attributed to a lack of lubrication -- was a cause of that accident, the Army has said.
Bruce Jay, a Boeing Vertol spokesman, said the bearing on the CH47D is manufactured by Litton Industries. He said that Boeing Vertol, a subsidiary of the Boeing Co., is assisting the Army in its inquiry.
The CH47D is the second Army helicopter to be grounded in recent weeks. The first was the UH60 Black Hawk, manufactured by the Sikorsky Aircraft division of United Technologies. Two recent Black Hawk crashes have killed 15 people, but the causes of the crashes are unknown. The Army has about 630 Black Hawks.