AeroVironment has confirmed the GO-1 Global Observer crashed early on 1 April, about 18h through its ninth test flight at Edwards AFB, California. The company has announced no further details about the mishap, but confirms "there are no reports of injury or damage to other property".

As an investigation board is convened, the crash occurs at a key moment for the high-altitude, ultra-long-endurance unmanned aircraft system sponsored by six government agencies.

A four-year demonstration programme had been scheduled to be completed on 31 March, but AeroVironment has yet to demonstrate that the liquid-hydrogen-powered aircraft can fly more than 5 days non-stop, as advertised.

“Flight testing an innovative new solution like Global Observer involves pushing the frontiers of technology and convention,” says AeroVironment chief executive Tim Conver. The company says the mishap occurred when GO-1 "had been operating for nearly twice the endurance and at a higher altitude than previous flights".

AeroVironment received a $120 million contract from the US Special Operations Command four years ago to demonstrate that GO-1 could operate as a quasi-satellite, relaying communications signals between units dispersed into Afghanistan’s mountains.

GO-1 achieved its first flight on 5 August 2010 powered only by batteries. After completing an initial round of flight tests in late September, AeroVironment installed the aircraft’s long-endurance engine that runs on liquid-hydrogen fuel.

 Global Observer UAV
© AeroVironment

The production of a second vehicle is nearly complete, AeroVironment says, but the programme’s status is unclear after the mishap.

Michael Lewis, an aerospace analyst for Lazard Capital Markets, believes the crash will delay the completion of the demonstration programme to “mid-to-late” 2012.

“With regard to cancellation, we don’t see this scenario as probable due to the time, resources and other successes already noted to date on the programme,” Lewis wrote in a note emailed to investors. “We don’t see the programme going away.”

The Global Observer cannot afford too many setbacks, however. Several competitors are also chasing the goal of ultra-long endurance flight. Boeing plans to demonstrate the liquid-hydrogen powered Phantom Eye later this year. Northrop Grumman also aims to conduct a seven-day flight with an RQ-4 Global Hawk, using mid-air refuelling rather than liquid-hydrogen as a fuel source.