HARTFORD, Conn. — A business jet flying over New England earlier this month pitched violently up and then down, killing a passenger, after pilots responding to automated cockpit warnings turned off a system that helps keep the plane stable. plane, US transportation investigators reported on Friday.
The National Transportation Safety Board did not reach any conclusions in its preliminary report about the main cause of the fatal March 3 accident, but it described a series of things that went wrong before and after the loss of control. plane.
Faced with multiple alerts in the Bombardier jet’s cockpit, the pilots followed a checklist and turned off a switch that “cuts” or adjusts the plane’s tail stabilizer, the report said.
The plane’s nose then swept upward, subjecting the people inside to forces about four times the force of gravity, then pointed downward before returning upward before the pilots regained control, the report said. saying.
The pilots told investigators they did not encounter turbulence, as the NTSB said in an initial review the day after the incident.
The trim system of the Bombardier Challenger 300 twin-engine jet was the subject of a Federal Aviation Administration mandate last year that pilots conduct additional safety checks before flights.
Bombardier did not directly respond to the report’s contents, saying in a statement that it was “carefully studying” it. In a previous statement, the Canadian manufacturer said it stands behind the Challenger 300 jets and their airworthiness.
“We will continue to fully support and provide assistance to all authorities as needed,” the company said on Friday.
The two pilots and three passengers were traveling from Keene, New Hampshire, to Leesburg, Virginia, before transferring to Bradley International Airport in Connecticut. A passenger, Dana Hyde, 55, of Cabin John, Maryland, was taken to a hospital where he died of blunt-force injuries.
Hyde served in government positions during the Clinton and Obama administrations and was an attorney for the 9/11 Commission, formally known as the National Commission on Terrorist Attacks Upon the United States.
It was unclear whether Hyde was strapped into his seat or up, in the cabin of the jet owned by Conexon, which is based in Kansas City, Missouri. Her husband and their son, along with the pilot and co-pilot, were not injured in the incident, the report said.
A representative of Conexon, a company that specializes in rural internet, declined to comment Friday.
The report indicated that the pilots aborted their first takeoff because no one removed a plastic cover from one of the outer tubes that determined the airspeed, and they flew there is a rudder fault alert.
Another warning indicates autopilot stabilizer trim failure. The plane suddenly pitched up as the pilots moved the stabilizer trim switch from primary to off while working through procedures on a checklist, the report said.
The plane oscillated violently up and down and the “stick pusher” was activated, the report said, meaning the onboard computer thought the plane was in danger of an aerodynamic stall.
John Cox, a former airline pilot and now a safety consultant, said there were “issues” with the pilots’ pre-flight actions, but he said they reacted correctly when they followed the checklist for in response to failure to cut.
The flight crew consists of two experienced pilots with 5,000 and 8,000 hours of flight time, and have the ratings required to fly for an airline. But both are relatively new to the aircraft model, having earned their ratings in October.
The FAA issued its directive regarding the Bombardier Challenger 300 jet last year after several instances where the aircraft’s horizontal stabilizer caused the nose of the aircraft to turn after the pilot attempted to board the aircraft.
