NTSB Details Possible Factors After Fatal Biz Jet Incident

Investigators are scrutinizing elevator trim and the aircraft’s autopilot as possible factors.

NTSB investigating a possible trim issue aboard a business jet after the aircraft encountered severe turbulence, resulting in the death of a passenger. [Credit: Shutterstock]

Problems with the autopilot and aircraft trim are being looked at as possible factors in an inflight upset that took the life of a passenger aboard a business jet earlier this month.

On March 3, a Bombardier Challenger 300 was flying from Dillant/Hopkins Airport (KEEN), Keene, New Hampshire, to Leesburg Executive Airport (KJYO) in Virginia. There were two pilots and three passengers on board. One of the passengers was a child.

According to the preliminary report issued by the National Transportation Safety Board (NTSB), the flight crew stated that the preflight inspection, engine start, and taxi for departure were routine. During the takeoff roll, however, the second-in-command (SIC) reported that although the airplane accelerated normally, he observed that the right primary flight display (PFD) airspeed indicator mis-compared to the left side airspeed indicator

The pilot-in-command (PIC) aborted the takeoff and exited the runway onto a taxiway and shut the left engine down. The preliminary data recovered from the airplane’s flight data recorder (FDR), showed that the airplane, during the first takeoff attempt, reached a maximum airspeed of 104 knots displayed on the left PFD airspeed indicator and 2 knots on the right PFD airspeed indicator before the abort was initiated.

The SIC exited the airplane and walked to the front of the aircraft, where he subsequently observed that the red pitot probe cover was still installed on the right-side pitot probe. The SIC removed the cover and returned to the cockpit, stating there was no damage to the probe.

The PIC restarted the left engine and resumed the taxi to the runway. Shortly after the left engine was restarted, the crew reported that an engine indicating and crew alerting system (EICAS) advisory message of ‘RUDDER LIMITER FAULT’ annunciated.

The PIC attempted two ground avionics “stall tests” to clear the message, as he had received this advisory message in past ground operations. However, the tests did not clear the annunciation. The flight was continued given that the message was an advisory and not a caution or warning.

During the subsequent takeoff, the flight crew further reported the acceleration was normal; however, the SIC noticed that the V-speeds were not set.

The SIC called V1 and rotate at 116 knots from memory, and the PIC entered the climb without incident.

As the initial climb and turn on course progressed, the PIC engaged the autopilot and they continued a climb to 6,000 feet msl. The flight was subsequently cleared to flight level 240 (24,000 feet msl).

According to the NTSB, "No significant difference in airspeed was observed in the data for the remainder of flight, following the SIC’s removal of the pitot probe cover. Throughout the initial climb, multiple pilot-commanded manual pitch trim inputs and corresponding movements from the horizontal stabilizer were observed."

During the climb, the preliminary FDR data showed that the autopilot had been engaged and disengaged in three separate instances. When the autopilot was engaged, there was an immediate master caution annunciated. The autopilot disconnected in the first two instances after the manual pilot pitch trim was activated, and small pitch oscillations were observed after the disengagement.

The flight crew reported that as the aircraft passed through 6,000 feet, they observed multiple EICAS caution messages. The crew recalled EICAS messages of ‘AP STAB TRIM FAIL’ (autopilot stabilizer trim failure), ‘MACH TRIM FAIL,’ and ‘AP HOLDING NOSE DOWN.’ Neither crewmember could recall exactly what order the EICAS messages were presented. They also reported that additional EICAS messages may have been annunciated.

The autopilot was re-engaged for the final time at 6,230 feet msl and remained on until reaching 22,780 feet msl. The airplane’s airspeed increased from 238 knots to 274 knots in this segment of the climb.

On the order of the PIC, the SIC referred to the quick reference handbook, locating the quick reference card and the ‘PRI STAB TRIM FAIL’ (primary stabilizer trim failure) checklist.

The SIC visually showed the PIC the checklist, and they both agreed to execute the checklist. The first action on the checklist was to move the stabilizer trim switch (‘STAB TRIM’), located on the center console, from ‘PRI’ (primary) to ‘OFF.’ The SIC read the checklist item aloud and he subsequently moved the switch to off.

As soon as the switch position was moved, the airplane abruptly pitched up. The PIC had his left hand on the yoke, and when the aircraft pitched up he put both hands on the yoke to regain control of the airplane, which pitched up and down for a few seconds. During the oscillations, the PIC instructed the SIC to move the stabilizer trim switch back to the primary position, which the SIC accomplished.

According to the NTSB, "The airplane immediately pitched up to about 11 degrees and reached a vertical acceleration of about positive 3.8g. The airplane subsequently entered a negative vertical acceleration to about negative 2.3g. The airplane pitched up again to about 20 degrees, and a vertical acceleration of positive 4.2g was recorded."

The stall protection stick pusher activated during this pitch up and subsequently, vertical acceleration lowered to about +2.2g which was followed by a cutout of FDR data.

The PIC reported that preceding the rapid pitch event, the autopilot was on, and he expected that once the stabilizer trim switch was turned off, the autopilot would disconnect, which it did.

No manual pitch trim inputs were recorded.

The PIC reported that he had no problem manually flying the airplane after the in-flight upset, nor did he experience any abnormalities trimming the airplane using the manual pitch trim switch, located on the control column, at any point during the flight. Shortly after the in-flight upset, the flight crew were alerted by a passenger that another passenger had been injured.

The SIC went to the cabin to provide medical attention for the injured passenger. He subsequently informed the PIC that there was a medical emergency and that they needed to land. The PIC contacted air traffic control, and the flight was diverted to Bradley International Airport (KBDL) in Connecticut.

The PIC did not reengage the autopilot for the remainder of the flight. After landing, the airplane taxied to the ramp where an ambulance was waiting. Paramedics entered the airplane and subsequently transported the injured passenger to a nearby hospital. The passenger succumbed to her injuries later in the day at the hospital.

The NTSB report did not indicate if the passenger had been wearing her seatbelt at the time of the inflight upset.

About the Flight

The accident airplane was managed by Executive Flight Services (EFS) LLC. and was a non-revenue Part 91 flight operated by the owner of the airplane, Conexon LLC.

In October 2022, both pilots completed initial ground and simulator training and earned their PIC type rating in the Challenger 300.

According to FAA airman records, the PIC held an airline transport pilot certificate and held a PIC type rating in the accident airplane, in addition to other type ratings held. The PIC had accumulated 5,061 total flight hours, and 88 hours in the accident make and model airplane.

The SIC held an airline transport pilot certificate and held a PIC type rating in the accident airplane, in addition to other type ratings held. EFS reported that the SIC had accumulated 8,025 total flight hours, and 78 hours in the accident make and model airplane.

The investigation is continuing.

Meg Godlewski has been an aviation journalist for more than 24 years and a CFI for more than 20 years. If she is not flying or teaching aviation, she is writing about it. Meg is a founding member of the Pilot Proficiency Center at EAA AirVenture and excels at the application of simulation technology to flatten the learning curve. Follow Meg on Twitter @2Lewski.

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