Experimental X-51A WaveRider Achieves Mach Speed During Flight Test

The U.S Air Force’s experimental, unmanned aircraft went hypersonic during a test off the Southern California coast, traveling at more than 3,000 mph, the Air Force said on Friday.

The Boeing X-51A WaveRider hit a speed of Mach 5.1 (about five times the speed of sound) and flew for more than three minutes under power of its exotic scramjet engine. The aircraft traveled more than 230 nautical miles in just over six minutes before crashing into the Pacific Ocean off the California coast as planned, according to the USAF.

Wednesday’s flight concludes the fourth and final flight test of the X-51A on which the Air Force has spent $300 million studying scramjet technology that it hopes can be used to deliver strikes around the globe within minutes.

The previous three flights ended in failure or didn't reach the intended speed.

Program officials said that they were satisfied with the WaveRider’s performance in the latest test although it was designed to reach Mach 6.

"It was a full mission success," program manager Charlie Brink of the Air Force Research Laboratory at Wright-Patterson Air Force Base said in a statement.

The sleek, missile-shaped WaveRider was released from a B-52 bomber 50,000 feet above the Pacific and was initially accelerated by a rocket before the scramjet kicked in.

It reached Mach 4.8 in less than half a minute powered by a solid rocket booster. After separating from the booster, the scramjet engine was ignited, accelerating the aircraft to Mach 5.1 at 60,000 feet.

The flight ended with a planned plunge into the ocean.

Darryl Davis, president of Boeing Phantom Works, which built the WaveRider, called the test "a historic achievement that has been years in the making".

"This test proves the technology has matured to the point that it opens the door to practical applications," Davis said in a statement.

While the Air Force did not have immediate plans for a successor to the X-51A, it said it will continue hypersonic flight research.