US aircraft achieves sustained hypersonic flight

A multi-million dollar American hypersonic aircraft has made its historic longest flight of three-and-a-half minutes at a speed five times that of sound, after a much talked about failure last year.
The unmanned aircraft, named X-51 Waverider, developed by Boeing is powered by a scramjet or a supersonic combustion air breathing engine that took the plane to a speed of Mach 5.1.
"It was a full mission success," said Charlie Brink, the X-51A programme manager for the Air Force Research Laboratory Aerospace Systems Directorate.
"I believe all we have learned from the X-51A Waverider will serve as the bedrock for future hypersonics research and ultimately the practical application of hypersonic flight," Brink said in a statement.

"The 4.3-meter long aircraft hit its top speed within six minutes of flight on May 1," said the US Air Force. "That is the longest of the it's four test flights conducted so far, and the longest air-breathing hypersonic flight ever."
The USAF added that X-51 is unique primarily due to its use of a hydrocarbon fuel in its scramjet engine. Other vehicles have achieved hypersonic, generally defined as speeds above Mach 5, flight with the use of hydrogen fuel. Without any moving parts, hydrocarbon fuel is injected into the scramjet's combustion chamber where it mixes with the air rushing through the chamber and is ignited in a process likened to lighting a match in a hurricane.