Four days after the crash of Virgin Galactic SpaceShipTwo vessel in the California desert, the US National Transportation Safety Board (NTSB) is hard at work to determine the causes of the accident that claimed the life of one of the two occupants.
The NTSB says it will take several weeks, possibly several months, to shed light on the in-flight breakup of the aircraft, but investigators have found that the crew had carried out an abnormal action on the rotating tail boom. By raising it perpendicular to the fuselage, it serves to slow the vessel at the time of descent before it re-enters the atmosphere.
Christopher Hart, Acting Chairman – NTSB: "There is a camera in the cockpit mounted on the ceiling that looks forward and shows that the feather lock/unlock lever was moved by the copilot from the lock position to the unlock position."
This action is normally only done when the aircraft reaches Mach 1.4 and not accelerating hard under full throttle, as was the case on 31st October. In approaching Mach 1, the tail boom may have been the cause of the vessel’s destruction. If for now, the investigators refuse to draw any conclusions, the fact remains that the sequence of events is troubling. In fact only two seconds separate the copilot’s de-activation of the system and the disintegration of the aircraft.
Regarding the new experimental fuel formula used during this flight, and which has attracted media attention since the accident, it is clear that in view of the initial information picked up from the crash site, there is nothing to incriminate it.
Christopher Hart, Acting Chairman – NTSB: "The fuel tanks were found intact, no indication of breech or burn-through and so was the engine as well."
Whether it was pilot error, structural failure, or incorrect fuel, it is obviously too early to draw any conclusions about this accident. The US National Transportation Safety Board believes that the investigation could take a year.