SpaceShipTwo crashed because feathering system was released early

Verge : After Virgin Galactic’s VSS Enterprise, an experimental SpaceShipTwo design, broke apart in flight last year, the National Transportation Safety Board (NTSB) found that the failure was due to the craft’s wings, which had shifted position. Now the agency has confirmed that the problem was caused by human error. In normal operations, the wings are moved into a “feathering” position as the craft reaches apogee in order to slow it down for reentry into Earth’s atmosphere. The NTSB’s investigation revealed, however, that the copilot unlocked the wings while the craft was still climbing and before it went supersonic. As the craft passed Mach 1, the force on the unlocked wings pushed them into feathering position. Because the craft was not in the proper orientation for the feathering maneuver, the resulting forces on the craft caused it to break up. Virgin Galactic said that it has now added an inhibitor that prevents the wings from being unlocked before the craft has reached Mach 1.4.