Boeing has announced taxi tests of Phantom Eye, the company's high-altitude, hydrogen-fuelled prototype unmanned air vehicle. The tests, which took place at Edwards AFB, California, bring the aircraft one step closer to its first flight.

The taxi tests occurred at medium speed, approximately 30kt (55km/h). They are the first taxi tests conducted on the aircraft, which lacks landing gear and is relies upon a cart to propel it to sufficient speed. An additional medium speed test is planned before moving to high speed taxi tests and, eventually, a first flight.

 Phantom Eye taxi - NASA


"It's a prototype, so we've never done this before. There's a lot of variables in doing something you've never done before," says Boeing. "We have a very strategic, piece-by-piece testing programme to go through, component-by-component, to identify anything that would be a risk before first flight."

The programme is roughly a year behind schedule. "It has a 150ft [45m] wingspan. It doesn't take a whole lot of wind to make it a bad test day," says the company.

Boeing confirmed ongoing discussions with potential customers, though it declined to provide additional details. No decision to produce additional aircraft is immediately forthcoming.

Source: Flight International