By Irene Klotz
CAPE CANAVERAL, Fla. (Reuters) - Test pilots at the helm of a Virgin Galactic passenger spaceship that crashed last year were unaware of the catastrophic consequences of unlocking the craft's moveable tail section too early because of poor training, investigators probing the fatal accident said on Tuesday.
The premature unlocking of SpaceShipTwo's hinged tail triggered a midair breakup of the ship during its fourth powered test flight on Oct. 31 over California's Mojave Desert, the National Transportation Safety Board has determined. Scaled Composites, a company the developed the craft and employed its test crew, provided inadequate training to co-pilot Michael Alsbury, who unlocked the tail, and pilot Peter Siebold,
the NTSB said during a hearing in Washington, D.C. on Tuesday.
Scaled, a subsidiary of Northrop Grumman Corp, should have informed the crew of what could happen to the craft when the tail section was unlocked prematurely. "Scaled did not consider that a pilot would induce that kind of failure," lead investigator Lorenda Ward said during the hearing, monitored via webcast. Scaled designed the two-pilot, six-passenger vehicle, for Virgin Galactic, a U.S. offshoot of Richard Branson's London-based Virgin Group. The craft was the first of a planned fleet of five vehicles that Virgin eventually expects to use to fly passengers on short, suborbital flights into space at altitudes of about 62 miles (100 km). It has already sold about 700 tickets for rides that cost $250,000 each. The Spaceship Company, a Virgin-owned operation based in Mojave, has taken over construction of SpaceShipTwo vehicles from Scaled. Test flights of its new ship are scheduled to begin before the end of the year. Alsbury, 39, an experienced test pilot, died in the accident, while Siebold, 43, managed to parachute to safety. Both pilots worked for Scaled Composites. The tail section is designed to rotate to allow the vehicle to re-enter the atmosphere with its heat-shielded belly down no matter what its original orientation. It is designed to be unlocked by one of the pilots after the ship is supersonic, traveling at about Mach 1.4, or 1.4 times the speed of sound. Alsbury unlocked the tail section when the spaceship was traveling at less than Mach 1. Virgin's spaceships will now include a mechanism to prevent pilots from unlocking moveable tail sections too early, the company wrote in an report to the NTSB that was released on Tuesday.
(Editing by Frank McGurty and Tom Brown)