" “About nine seconds after the engine ignited, the telemetry data showed us that the feather parameters changed from lock to unlock,” Hart said.
According to Hart, a camera mounted inside SpaceShipTwo’s cockpit showed Alsbury move a handle to unlock the feather system as the rocket plane passed Mach 1 — the speed of sound.
Such action on a SpaceShipTwo flight is not expected until the rocket plane reaches Mach 1.4, Hart told reporters in a press conference Sunday night in Mojave, Calif.
“Normal launch procedures are that after the release, the ignition of the rocket and acceleration, that the feathering devices are not to be moved — the lock/unlock lever is not to be moved into the unlock position — until the acceleration up to Mach 1.4. Instead, as indicated, that occurred (at) approximately Mach 1.0,” Hart said.
The tail booms extended after they were unlocked, even though they were not commanded to do so, Hart said.*SpaceShipTwo’s pilots normally must unlock the feathers, then send a separate command to move the tail booms into position for descent.
“This was what we would call an uncommanded feather, which means the feather occurred without the feather lever being moved into the feather position,” Hart said.
“After it was unlocked, the feathers moved into the deployed position, and two seconds later we saw disintegration,” Hart said."
Conferenza stampa NTSB.