Wednesday, November 24, 2004
Experimental chopper loses part of blade
By Chris Lambie

A cutting-edge U.S. military aircraft being tested in our skies made an emergency landing at Shearwater on Friday after losing a chunk of rotor blade.
The tilt-rotor V-22 Osprey lost a 50-centimetre-long piece of rotor blade somewhere near the shoreline.

“They were flying along the water when this occurred, not over a populated area,” said Kirsti Dunn, of Boeing Co., the U.S. aviation giant that built the aircraft with Bell Helicopters.

About 20 kilometres from Shearwater, the crew noticed unusual vibrations and noises that sounded like ice shedding off the rotors.

“Any time you have something (where) there may be some impact on the blade, you want to get your aircraft down as quickly as possible,” Dunn said.

The Osprey returned to Shearwater by taking a route over the ocean, she said.

“If anything is coming off the aircraft, even big chunks of ice, you don’t want it falling and damaging anyone or anything,” Dunn said.

The first clue that something was going wrong came from cockpit indicators showing a heater failure on the left side of the aircraft, she said.

Investigating

“Sensing that there was something going on with the rotor blades, they did declare the emergency and slowed the aircraft to minimize vibrations.”

It landed safely, and the U.S. military is now investigating what caused the problem.

The Osprey — which is here to test de-icing capabilities — can normally run an electric current through the wings and its twin giant rotors to warm them and melt ice.

“They’re thinking it was ice that hit it,” Dunn said of the damaged rotor. “But where did it come from?”

The investigation may include placing more cameras on the Osprey to get a better idea of where ice forms and sheds.

The damaged section of rotor, about 10 centimetres wide, has not been found, she said.

The Osprey went into a scheduled maintenance period after the emergency landing and won’t be able fly again until Dec. 6.

“They’re replacing this blade, so the airplane will be flyable,” Dunn said.

The Osprey — which started test flights out of Shearwater earlier this month — is equipped with an 11-metre rotor on the end of each wing, allowing it to fly like a plane.

The rotors tilt 90 degrees when the Osprey wants to lift off or land vertically, like a helicopter.

Grounded in 2000

Osprey tests at Shearwater were cancelled four years ago when the fleet was grounded following two Osprey crashes in the U.S. that killed 23 Marines.

In July 1992, a test Osprey crashed into the Potomac River, killing four Boeing employees and three Marines.

clambie@hfxnews.ca

http://www.hfxnews.ca/