WASHINGTON — The pilot that survived the Oct. 31 crash of Virgin Galactic’s SpaceShipTwo has told federal investigators he was unaware that the vehicle’s co-pilot, who died in the accident, had unlocked the vehicle’s feathering mechanism prematurely.

The U.S. National Transportation Safety Board (NTSB) said in a Nov. 12 statement that its investigators interviewed the vehicle’s pilot Nov. 7, a week after the accident. The statement did not identify the pilot by name, but he was previously identified as Peter Siebold, the director of flight operations for Scaled Composites, the company conducting the test flight for Virgin Galactic.

The investigation has focused on the premature deployment of SpaceShipTwo’s feathering mechanism, designed to raise the vehicle’s twin tail booms during re-entry. The NTSB previously said telemetry and video from the flight indicated that SpaceShipTwo’s co-pilot, Michael Alsbury, unlocked the feathering system 9 to 11 seconds after engine ignition, as the vehicle reached Mach 1. The vehicle broke apart several seconds later.

The unlocking of the mechanism took place several seconds earlier than planned, but Siebold told the NTSB he had no knowledge of Alsbury’s actions. “According to the pilot, he was unaware that the feather system had been unlocked early by the copilot,” the NTSB said in its statement.

While Siebold did not know about the unlocked feathering system, the NTSB said his recollection of the flight matched other data. “His description of the vehicle motion was consistent with other data sources in the investigation,” the NTSB said in its statement, but it offered no other details.

Although Alsbury was killed in the accident, Siebold survived with relatively minor injuries, despite the vehicle’s breaking apart at an altitude of about 15,000 meters. Siebold told the NTSB that he was “extracted” from SpaceShipTwo as the vehicle broke apart, and he later unbuckled from his seat. His parachute deployed automatically.

The Nov. 12 statement from the NTSB is the first update of the accident investigation by the agency since a Nov. 3 press conference at the Mojave Air and Space Port in California. The NTSB said that it has concluded the on-scene portion of the investigation, and its staff has returned to NTSB headquarters here.

The Oct. 31 accident spread debris from SpaceShipTwo over a swath about 8 kilometers long in the Mojave Desert north of the spaceport. The NTSB said that debris has been recovered and “is being stored in a secure location for follow-on examination.”

Other NTSB investigators are examining telemetry and video from the flight, including data stored in nonvolatile recorders on the vehicle itself. They are also examining the components of SpaceShipTwo’s feathering system and vehicle documentation.

The NTSB statement gave no timeline for completing the investigation. At the Nov. 3 press conference, NTSB Acting Chairman Christopher Hart said it could take up to a year for the agency to complete its investigation and publish its findings.

Despite that schedule for the investigation, Virgin Galactic officials have stated they will press ahead with the assembly of a second SpaceShipTwo, which was already under construction at the time of the accident. Company Chief Executive George Whitesides told CNN Nov. 9 that the vehicle could be ready for test flights within six months.

“The second SpaceShipTwo is already two-thirds complete, and our team are pouring themselves into that project with heightened resolve,” Virgin Galactic said in its most recent public statement about the accident, issued Nov. 7.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...