Pilots reveal theory on Osprey design flaws

Friday, April 6, 2001

The Marine Corps (www.usmc.mil) knew about a design flaw in the Osprey hybrid helicopter-airplane before it caused two fatal crashes in the past year, say unnamed Marine Corps pilots who were investigating the incidents.

Osprey crashes last December (in North Carolina) and April (in Arizona) have killed a total of 23 Marines in 2000. There were also seven killed in a crash in 1992, and a nonfatal crash in 1991.

The Marine pilots announced yesterday that the Pentagon (www.defenselink.mil) knew about a flaw in the hydraulic system that was compounded by a software glitch, but were reluctant to address the problem because they thought it would risk federal funding for the plane.

Marine investigators have long suspected that the hydraulic system was to blame, but they did not know that senior Marine officers already knew about the problem.

At stake is an order of 360 of the MV-22 tilt-rotor planes, which are built jointly by Boeing (www.boeing.com/rotorcraft/) and Textron's Bell Helicopter Div. (www.textron.com/businesses/aircraft/profile.html). The aircraft can take off vertically like a helicopter and then rotate its two propellers to fly like a normal airplane.