Facebook's solar-powered drone under investigation after 'accident'

Social network's plan to bring 1 billion people online suffers blow as American National Transportation Safety Board examines 'structural failure' of Aquila drone

Facebook has hit a hitch in its plans to use a solar-powered unmanned drone to provide internet access to developing nations, after it was revealed the American National Transportation Safety Board (NTSB) has opened an investigation into an accident on the drone's first test flight in June.

At the time, Facebook described the flight as "successful": the drone, called Aquila, stayed aloft for 96 minutes, three times the planned duration. "We have a lot of work ahead of us," Jay Parikh, Facebook's head of engineering and infrastructure, wrote when Facebook revealed the test flight, in late July. "In our next tests, we will fly Aquila faster, higher and longer, eventually taking it above 60,000 feet."