DARPA Verifies "Global Strike" Glider's Ocean Crash

An autopilot mechanism guided a U.S. hypersonic drone aircraft to an unplanned landing in the Pacific Ocean after the glider encountered a "flight anomaly" during a test last week, the Defense Advanced Research Projects Agency said on Sunday (see GSN, Aug. 12).

The Hypersonic Technology Vehicle-2 hit the anomaly "post-perigee" and during its ascent, the Defense Department agency said in a press release. The glider is one system being considered to provide the United States with the "prompt global strike" capability to deliver non-nuclear warheads to any location in the world within an hour.

“We’ve confirmed that the HTV-2 made impact with the Pacific Ocean along its flight trajectory as planned in the event of an anomaly,” Air Force Maj. Chris Schulz, who heads the glider program, said in the release. “This flight safety system is a significant engineering advance in that the system prompts a vehicle to monitor the parameters under which it is operating and exercise safety protocols completely autonomously should those parameters be breached.”

An initial examination of information sent out by the aircraft before the unforeseen event suggests the system "demonstrated stable aerodynamically controlled Mach 20 hypersonic flight for approximately three minutes," DARPA Director Regina Dugan said in the statement.

The glider failed in its initial trial flight, conducted in April 2010 (see GSN, Aug. 19, 2010). Responding to findings on last year's test by an autonomous Engineering Review Board, specialists in the latest exercise altered the aircraft's center of mass, reduced its angle of attack flown and modified its flaps using internal reaction control units.

“It appears that the engineering changes put into place following the vehicle’s first flight test in April 2010 were effective," Dugan said. "We do not yet know the cause of the anomaly for Flight 2."

Schulz added: “An initial assessment indicates that the Flight 2 anomaly is unrelated to the Flight 1 anomaly."

An autonomous Engineering Review Board in the next few weeks is set to study the likely reasons behind the latest flight troubles, according to the DARPA release (U.S. Defense Advanced Research Projects Agency release, Aug. 14).

August 18, 2011
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An autopilot mechanism guided a U.S. hypersonic drone aircraft to an unplanned landing in the Pacific Ocean after the glider encountered a "flight anomaly" during a test last week, the Defense Advanced Research Projects Agency said on Sunday (see GSN, Aug. 12).