An airframe component that functioned correctly on two previous flights caused the failure of the third flight of the U.S. Air Force's Boeing X-51A Waverider hypersonic vehicle.A faulty fin caused the cruiser to go out of control before its scramjet engine could be ignited.
Here's the Air Force's statement:
"The X-51A Waverider successfully launched from an Air Force B-52 bomber over Point Mugu Naval Air Warfare Center Sea Range Aug. 14 at approximately 11:36 a.m. PST.
The X-51 safely separated from the B-52 and the rocket booster fired as planned. However after 16 seconds, a fault was identified with one of the cruiser control fins. Once the X-51 separated from the rocket booster, approximately 15 seconds later, the cruiser was not able to maintain control due to the faulty control fin and was lost.
"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 Air Force Research Laboratory. "All our data showed we had created the right conditions for engine ignition and we were very hopeful to meet our test objectives."
Program officials will now begin the process of working through a rigorous evaluation to determine the exact cause of all factors at play.
One of the four X-51A vehicles remains. AFRL officials have not decided when or if that vehicle will fly at this time."