Pilot Errors, Not Turbulence, Caused Fatal Upset

In a final report that seems scripted to prove the old adage about aircraft accidents resulting from a series of seemingly minor mishaps, the NTSB has determined that pilot actions, not turbulence and later a trim issue, as was widely reported at the time, caused an upset that led to the death of a passenger on a Challenger 300 in 2023. The board said the chain of events began with a forgotten pitot cover and progressed through a cascade of errors and missteps that ended with a 4G upset and loss of control.

During the upset, a female passenger, who was not wearing a seatbelt, suffered a serious head injury and later died in a hospital. "The crew’s continuation of the flight with an unairworthy airplane directly contributed to the subsequent series of [Crew Advisory System] messages, which the crew mis-diagnosed during the climb, resulting in the in-flight upset and loss of airplane control," the report said.

The Challenger was chartered to fly three passengers from Keene, New Hampshire, to Leesburg, Virginia, on March 3, 2023. The same plane had brought them to Keene the day before. During preparation for the flight, the second-in-command pilot was interrupted on his walkaround and forgot a pitot cover. That resulted in an aborted takeoff when airspeed readings disagreed. The crew did not consult their emergency checklist, which said the disagreement and aborted takeoff was a "No-Go" situation requiring a call to maintenance. Instead, they stopped on a taxiway, the SIC retrieved the pitot cover and they prepared to take off again. The panel showed a Rudder Limiter Fault advisory but rather than consult the corresponding checklist, which identified it as a No-Go item, the crew elected to troubleshoot it themselves after takeoff.

The aborted takeoff had resulted in errors being recorded in the horizontal stabilizer trim electronic control unit (HSTECU), which in turn resulted in a series of advisories beginning with the Rudder Limiter Fault indication. After a series of troubleshooting steps the captain turned off the autopilot and the aircraft underwent a series of pitch changes that reached 4Gs before control was regained. After learning about the passenger's injury, the SIC performed first aid and the flight diverted to Windsor Locks to get her to a hospital.

The NTSB says the original error and subsequent panel warning was an easy fix. Had the crew contacted maintenance as required by the checklist, they would have been told to power down the airplane and restart it, clearing the errors that had been set during the aborted takeoff. The plane's systems had apparently functioned as designed throughout the incident.