The US Marine Corps plans to press ahead with the completion of Bell Boeing MV-22B Osprey operational evaluation (Opeval) and a full-rate production decision in October, despite the unexplained fatal crash of a tiltrotor during a training exercise.
Opeval is due to be completed by June and its success will determine the decision on launching full-rate production of a planned 360 tiltrotors for the USMC. "There is no doubt in my mind that the full rate production decision will be made with milestone III and that it will go through," says Lt Gen Fred McCorkle, USMC deputy chief of staff aviation.
The crash, on 8 April at Marana regional airport, Arizona, destroyed one of four low-rate initial production MV-22s participating in Opeval, killing four crew and 15 marines.
An eyewitness in another MV-22 reports seeing the MV-22 in a hover at around 200ft (60m) off the ground when it pitched nosedown, yawed to the right and hit the ground. Transition to the hover was completed and there was no fire or explosion before impact.
During MV-22 sea trials, a lateral control problem in high winds was discovered. The USMC says this was fixed with a software modification to the digital flight control system (Flight International, 14-20 April,1999). The tiltrotor's 227 parameter flight data recorder has been recovered.
Flight conditions during the evening time exercise are described as good, with little or no wind and 17% illumination. Remaining MV-22Bs have been temporarily grounded.
Source: Flight International
