X-51A Hypersonic Test Flight Ends Prematurely
August 16, 2012 - The anticipated hypersonic flight of the X-51A Waverider ended prematurely on Tuesday, August 14, due to a fault with one of the cruiser control fins, the U.S. Air Force announced in a statement Wednesday. The flight in the scramjet-powered aircraft was expected to last five minutes and achieve a speed of Mach 6 (3,600 mph) but was over in about a half-minute.
The statement said the X-51A successfully launched from an Air Force B-52 bomber over Point Mugu Naval Air Warfare Center Sea Range at approximately 11:36 a.m. Pacific Standard Time. The rocket booster fired as planned, but after 16 seconds, the fault was identified with one of the cruiser control fins. Fifteen seconds later after separating from the rocket booster, the cruiser was not able to maintain control due to the faulty control fin and was lost, apparently falling into the Pacific Ocean.
"It is unfortunate that a problem with this subsystem caused a termination before we could light the Scramjet engine," said Charlie Brink, X-51A program manager for the Air Force Research Laboratory (AFRL). "All our data showed we had created the right conditions for engine ignition and we were very hopeful to meet our test objectives."
Officials were especially optimistic since the same control subsystem proved reliable in two previous test flights, including in May 2010 when the Waverider flew for more than three minutes at Mach 4.88 under scramjet power, or nearly five times the speed of sound.
A rigorous evaluation is under way to determine the exact cause of the flight failure, the statement said. Also, there's only one of four original X-51A aircraft left, and a decision as to whether it will fly has not been made.