Air Force’s second hypersonic Waverider flight set for March 22

The Air Force plans a second hypersonic flight test next week of its X-51A Waverider aircraft, hoping that some improvements will avoid a problem that cut short last year’s first flight.

The date of the flight over the Pacific Ocean is March 22, if plans don’t change before then, said Charlie Brink, X-51A program manager with the Air Force Research Laboratory’s propulsion directorate at Wright-Patterson Air Force Base. He and other project officials spoke with reporters Tuesday on a conference telephone call.

Once again, a B-52 from Edwards Air Force Base, Calif., is to carry the Waverider aloft under a wing and release the aircraft at about 50,000 feet over the Pacific Ocean. A solid rocket booster will then accelerate the Waverider before its air-breathing scramjet (short for supersonic combustion ramjet) engine kicks in for what the Air Force hopes will be a four-minute flight reaching the speed of Mach 6, six times the speed of sound.

The 14-foot-long aircraft is called the Waverider because it rides its own shockwave.

The initial May 2010 flight had to be terminated after slightly more than two minutes, when the Waverider had reached Mach 5, on the way to a hoped-for Mach 6. The military controller intentionally sent the Waverider crashing into the Pacific after controllers lost contact with the high-speed vehicle, Brink said.

A failed seal at a nozzle caused hot gases to build up inside the Waverider, rather than go out the back of the nozzle, Brink said. Engineers have made improvements they hope will avoid a repeat, he said.

It is the second of four test flights for the $246.5 million Waverider program, begun in December 2003. It is being done to demonstrate technology the Air Force hopes can eventually be used for more efficient transport of payloads into orbit.

The flights are all to end with crashing the Waveriders into the Pacific. The Air Force determined that, at the speed they fly, the Waveriders would sink before ships could get to where the aircraft hit the water, Brink said.

“Of the existing X-51s, there is no plan to modify them to be recoverable,” he said.

Boeing Co. built the aircraft. Pratt & Whitney Rocketdyne built the scramjet engine.


Source:
By John Nolan, Staff Writer - Tuesday, March 15, 2011
WRIGHT- PATTERSON AIR FORCE BASE — Dayton Daily News

Photo:
An Air Force Flight Test Center B-52 Stratofortress from Edwards Air Force Base, Calif., carries an X-51A Waverider prior to the scramjet’s first hypersonic flight test on March 26, 2010. Air Force engineers have made design modifications to the three remaining X-51A demonstrators and plan to resume the hypersonic flight test program in early spring of 2011. (U.S. Air Force photo)

(17.03.2011)