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Oh, By The Way, We Need A New Engine
This sucker should have been cancelled a decade ago.
The V-22 has made another bid for a Cleopatra award - presented by Ares to programs that are terminally snake-bitten - by the revelation, almost casually tossed out in mid-press conference at the Navy League show by program manager Col. Matt Mulhern, that the AE 1107C engines are not lasting long enough in service and that the Navy "could go as far as re-engining the airframe".

Swapping engines is not trivial. It involves redesigning the engine nacelle and all its associated systems and repeating much of the flight test program. Mulhern wasn't giving any cost estimates, but we're talking several hundred million dollars at the minimum. The fact that the Navy is even talking about such a move says that the existing engine is not performing acceptably and that nobody's quite sure how much it will cost to fix.

The problem has to do with lifetime. All engines lose performance with age, as heat, stress and contaminants take their toll on blades and seals. The result is that the engine gets less efficient and has to run hotter to produce rated power, and eventually temperatures reach a limit. Mulhern won't say how long the current engine is lasting, but it's somewhere between a few hundred hours - which the Navy feared was going to be the engine's lifetime in Iraq - and several thousand, which Rolls-Royce predicted and used as the basis for its power-by-the-hour contract.

Mulhern says that he's not sure that the government ever believed Rolls-Royce's estimates, which does raise the question of why program officials signed that contract in the first place. However, it's not hard to realize what would have happened if the need for a new engine had been disclosed a few years ago, when the V-22 program was reeling from a series of accidents and the need for an extensive redesign.

Fortunately, there is an alternative engine available - the General Electric GE38-1B, under development for the CH-53K. Which is ironic, because - as the few of us who were in this business when the V-22 got started will recall - the GE38's design roots are in a project called the Modern Technology Demonstrator Engine, which was originally intended to be the definitive V-22 engine. But the AE 1107C was sold, back then, as a lower-risk alternative.

Meanwhile, the Marines are saying very little about operational experience in Iraq - and won't until the first operational squadron crews return in about a month. Which, coincidentally, will be after the Pentagon signs a multi-year contract for 167 more aircraft.
Posted by: Steve White 2008-03-19
http://www.rantburg.com/poparticle.php?ID=234369