PAUL LEWIS / WASHINGTON DC
Programme sources suggest government has political agenda behind approval delay
US Department of Defense officials are warning that the cost effectiveness of the US Marine Corps' Bell Boeing V-22 Osprey programme is still under scrutiny, despite a report from a NASA-led independent assessment panel recommending resumption of flight testing and operational deployment of the tiltrotor as soon as possible.
The NASA report comes at a critical juncture as industry and the marines press defence undersecretary for acquisition Pete Aldridge to commit to the V-22's long-term future. But DoD sources say Aldridge is still sceptical about the technology and its economics.
Still pending is a USMC analysis of alternatives, which is due to be completed by early December, and an annual end of year review of all programmes.
In the absence of political approval, the V-22 cannot move beyond barely sustainable low-rate initial production. It has been grounded for almost a year since the second fatal crash of a USMC MV-22B in December last year and under the restructured development and test programme it will not fly again before April.
"There is no scientific body more respected than NASA and they have thoroughly endorsed tiltrotor technology. Anyone who is still against this scheme cannot be against it for technology, there has to be another agenda," says a programme source. The panel of 12 vertical flight experts, which was drawn from industry, academia and government, was unequivocal in its findings.
"The conclusion of the panel is that there is no known aero-mechanical phenomena that would stop the safe and orderly development and deployment of the V-22. The panel recommends that the development flight test programme be resumed without delay."
The panel was charged with assessing aeromechanical phenomena that might affect V-22 safety and performance, such as vortex ring state, which caused an MV-22 crash. The panel made recommendations to be implemented as soon as possible, as well as suggesting longer term enhancements.
The former include the better display of descent-rate information, expanded flight testing to define vortex ring state boundaries with greater accuracy, to determine if a warning system is needed and incorporate a vortex ring-state model into simulators.
Other recommendations include developing better recovery procedures for single and both engines inoperative, as well as more low speed/wind azimuth envelope, expanded shipboard compatibility, and formation and hover flight testing. The panel suggested additional resources be given to the V-22 Integrated Test Team to ensure timely completion of flight testing.
"Given the evolving mission of our armed forces in the 21st century, the panel believes that this vehicle should be deployed at the earliest opportunity," it says.
Source: Flight International
