How it happened- from chair NTSB - WSJ
SpaceShipTwo's unique tail section, which can "feather" at an angle to help the Virgin Galactic spacecraft make a safe descent, unfurled as it was ascending during the flight that ended in a fatal breakup Friday and without being ordered to do so, federal investigators said Sunday night.
The "feathering" mechanism isn't supposed to be unlocked until the spacecraft reaches 1.4 times the speed of sound, Christopher Hart, the NTSB's acting chairman, said at a news conference. But on the flight that crashed Friday, co-pilot Michael Alsbury moved the mechanism's lock-unlock lever into the unlocked position earlier, at just slightly above Mach 1, Hart said.
The "feathering" procedure is supposed to require two separate steps to engage: First, a pilot must unlock the feather parameter; then he or she must move a feather handle into position. SpaceShipTwo's feather mechanism began moving almost immediately — even though neither pilot took that second step,