LOS ANGELES – Pete Siebold, the surviving member of the two-man SpaceShipTwo test crew, has revealed how he was thrown clear of the suborbital spaceplane as it disintegrated at around 50,000 ft. over the Mojave Desert during a powered test flight on Oct 31.

Siebold, who was airlifted from the crash site to Antelope Valley Hospital with severe injuries, told National Transportation Safety Board (NTSB) investigators on Nov. 7 that he "was extracted from the vehicle as a result of the breakup sequence and unbuckled from his seat at some point before the parachute deployed automatically." Siebold’s survival is all the more remarkable given SS2 is not equipped with ejection seats and, since the vehicle is pressurized, the crew flies without pressure suits.

The accident occurred during the first few seconds of a powered flight, shortly after release from the WhiteKnightTwo carrier aircraft that takes SS2 to launch altitude. Data from the flight indicates the feathering system, which is designed for use during re-entry, deployed during the critical acceleration phase around Mach 1.02. The deployment was uncommanded, and occurred approximately 2 sec. after co-pilot Mike Alsbury unlocked the feathering system. According to the NTSB, Siebold was "unaware that the feather system had been unlocked early by the co-pilot. His description of the vehicle motion was consistent with other data sources in the investigation."

The NTSB confirms the on-scene portion of the investigation is over and the wreckage of SS2 has been recovered and is being stored in "a secure location for follow-on examination." The safety agency adds that an investigative group will convene next week at the NTSB Recorders Laboratory in Washington, D.C. to review the video camera footage. The systems group also "continues to review available data for the vehicle’s systems," while the vehicle performance group is examining the aerodynamic and inertial forces that acted on the vehicle during the launch.