The crash of a Gulfstream jet that killed a prominent businessman and six others two weeks ago was likely caused by flight controls that weren't working properly because they were erroneously locked in parked position, the National Transportation Safety Board (NTSB) on Friday.
The agency also said that a review of the cockpit recorders and evidence reveals that the pilots failed to perform a preflight check of those flight controls, a basic precaution that would have prevented the tragedy.
The crash of the Gulfstream IV at Hanscom Airport outside of Boston drew much attention, and not just due to the high profile of its owner, Lewis Katz, a sports-franchise tycoon from Philadelphia who was returning home after a fundraising event. Given the experience of the pilots, each of whom had more than 10,000 hours of flying experience, much of it on that very same model, aviation experts were initially baffled. The Gulfstream IV is a highly reliable business jet and one of the manufacturer's top sellers, with 500 in service.
"It has a stellar record," says John Goglia, a former member of the NTSB who is now an aviation consultant.
The initial report lays out the scenario of what happened based on the evidence so far. The plane had flown up from Atlantic City earlier in the day and was set to depart on its return trip shortly after 9:30 pm. At that time it began rolling down the 7,000-foot runway, gaining speed up to 190 mph but, as one witness observed, with "little to no altitude gained." It then tumbled off the end of the runway and onto the grass, striking an antenna before coming to a final stop in a gully and bursting into flames. The postcrash fire destroyed much of the aircraft behind the cockpit. The entire voice recording of the flight, which begins with the takeoff roll, is a mere 49 seconds. In effect, the plane never got off the ground.
The recording also shows that the pilots quickly realized something was wrong. What they likely didn't realize is that the flight controls were set in a "gust lock" position that essentially secures the elevator and rudder to protect those surfaces from wind gusts while parked. But even if that happens, the plane's engines have a built-in safety feature that's supposed to prevent the crew from adding power to avoid this exact scenario. Why that didn't work in this case is still under investigation. There also is no evidence of an engine failure or any other breakdown during takeoff, the NTSB said.
The NTSB found evidence the crew did try to abort takeoff. The report noted tire marks on the runway and that the thrust reversers, which are used to slow the plane down, were activated. But it was too late: The plane was accelerating too fast to stop before it began its fatal tumble down the hill.
Goglia said that while it's clear pilot error played a major role, it doesn't explain the entire sequence of events. "This is only one part of the puzzle," he says, and much will emerge in the next few months about the pilots, as well as the aircraft, that could solve the mystery of how a highly experienced crew could have missed a simple glitch that ultimately doomed their flight.