Christopher Hart, NTSB
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Did 'feathering device' cause Virgin Galactic crash?

A safety device on the Virgin Galactic spacecraft that crashed on Friday deployed too soon, according to US investigators.

Christopher Hart, from the US National Transportation Safety Board (NTSB), said that "a feathering device" was designed to be activated at Mach 1.4, but deployed early during the flight.

Speaking to the BBC's David Willis, he said one of the pilots had enabled the device, but that the second stage of its deployment could have happened "without command from the pilots".

Go to next video: On the ground at Virgin crash site