WASHINGTON D.C.: The US National Transportation Safety Board has said that after an automated cockpit warning that switched off a system that helps keep aircraft stable, a business jet flying over New England violently pitched upward then downward, killing one passenger.
In its preliminary report on the cause of the accident on 3rd March, the Transportation Safety Board said there was a series of events that went wrong before and after the plane lost control, but it did not offer any conclusions.
The report said that after seeing several alerts in the cockpit of the Bombardier jet, pilots followed a checklist and turned off a switch that "trims" or adjusts the stabilizer on the plane's tail.
After the plane's nose swept upwards, the passengers and crew were subjected to forces about four times the force of gravity, the report added.
Pilots told investigators they did not encounter turbulence before the incident.
Last year, the trim system of the Bombardier Challenger 300 twin-engine jet was the subject of a Federal Aviation Administration mandate, which required pilots to conduct extra pre-flight safety checks.
In a statement, Bombardier said it was "carefully studying" the report's contents, but it has previously said it stood behind its Challenger 300 jets and their airworthiness.
"We will continue to fully support and provide assistance to all authorities as needed," company officials said in a statement.
John Cox, former airline pilot and safety consultant, said, "There are definitely issues with the pilots' pre-flight actions, they reacted correctly when they followed the checklist for responding to trim failure," as quoted by the associated Press.
After several incidents in 2022 in which the horizontal stabilizer on the aircrafts caused their noses to turn down after pilots tried to make the aircraft climb, the FAA issued its directive about Bombardier Challenger 300 jets.