N300ER

HISTORY OF FLIGHTOn March 3, 2023, about 1600 eastern standard time, a Bombardier BD-100-1A10 (Challenger 300) airplane, N300ER, was involved in an accident near Windsor Locks, Connecticut. One passenger was fatally injured. The two airline transport pilots and two other passengers were not injured. The airplane incurred minor damage. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

The flight crew reported that they completed a flight from Leesburg Executive Airport (JYO), Leesburg, Virginia, to Dillant/Hopkins Airport (EEN), Keene, New Hampshire, with the accident passengers the day before the accident. The accident flight was the return flight to JYO and the first flight of the day.

The SIC conducted an exterior preflight inspection of the airplane. His inspection was interrupted when he stopped to assist an employee of the fixed base operator who had brought ice to the airplane. After assisting the lineman, he resumed the preflight inspection where he thought he had stopped; however, he inadvertently left the non-streamer pitot cover on the right pitot probe. The PIC also did not observe the pitot probe cover and reported that the SIC had completed the exterior preflight checklist. The passengers arrived about 1500 boarded the airplane, and the pilots conducted an uneventful engine start and taxi.

During the takeoff roll on runway 2, the SIC reported that the airplane accelerated normally; however, he observed that the right primary flight display (PFD) airspeed indicator failed to show an acceleration above 40 knots (kts), while the left airspeed indicator showed a normal acceleration. The crew rejected the takeoff, and the PIC slowed the airplane without issue and exited the runway onto a taxiway.

According to data recovered from the flight data recorder (FDR), the takeoff was initiated at 1526:11 and was subsequently aborted about 16 seconds later. The airplane reached a maximum speed of 104 kts, as indicated by the left PFD; however, the data for the right PFD airspeed indicator was consistent with the probe remaining covered.

Following the rejected takeoff and exit from runway 2, the left engine was shut down on the taxiway, and the SIC opened the main cabin door and walked to the front of the airplane, where he subsequently observed that the red pitot probe cover remained installed on the right side pitot probe. The SIC removed the cover, did not see any damage to the probe, and returned to the cockpit.

While the SIC was retrieving the pitot probe cover, the PIC observed a Crew Alerting System (CAS) cyan advisory “RUDDER LIMITER FAULT” message. The PIC reported that he attempted two avionics stall tests (STALL/ RUD LIM test) to clear the message, as he had received this advisory message on previous flights in environments where the airplane was cold soaked; however, the tests did not clear the annunciation.

The cockpit voice recorder (CVR) captured the flight crew discussing the Rudder Limiter Fault message and that the flight director was in pitch mode. After the SIC observed the Rudder Limiter Fault CAS message, he stated, “I’ll call ‘em,” and the PIC responded with, “who you calling?” The SIC stated, “do you want to take off with a rudder limiter fault?” The PIC responded with “it’s advisory only.” Their discussions continued briefly and eventually both agreed to continue the flight with the advisory message displayed.

The crew again taxied for takeoff, entered runway 2, and began the takeoff roll. According to the PIC, the flight director command bars on the attitude pitch indicator would not appear after pressing the takeoff button, but he elected to continue with the takeoff. According to the SIC, about 80 kts, he noticed that there were no V-speed bugs displayed on the airspeed indicator, but he remembered from their previous takeoff attempt that the V1 (decision) speed was 116 kts. The SIC announced “V1” about 116 knots, followed by “rotate.” The airplane became airborne at 1535:27.

The PIC reported that the autopilot was engaged during the initial climb and the turn onto course, and the crew continued a climb to 6,000 ft mean sea level (msl).

During the climb, the flight crew observed multiple CAS caution messages. The crew recalled messages of “MACH TRIM FAIL,” “AP STAB TRIM FAIL” [Autopilot Stabilizer Trim Failure], and “AP HOLDING NOSE DOWN.” Neither crewmember could recall exactly what order the CAS messages were presented throughout the climb, or whether other messages were displayed.

About 1536:11, the flight was cleared by air traffic control to climb to FL230 (23,000 ft msl).

According to the CVR, at 1536:28, the SIC asked the PIC if he wanted a lower altitude, and the PIC responded with, “no … get the checklist.” The SIC subsequently attempted to re-input the V-speeds into the flight management system (FMS) and stated, “I think it’s a configuration issue from the beginning.” At 1536:52, the sound of a cavalry charge, consistent with an autopilot disconnect, was heard. The SIC questioned the PIC whether the autopilot had failed or whether the PIC disconnected it, to which the PIC stated, “I did that.”

According to the FDR, following the initial disconnect at 15:36:52, the autopilot was reengaged two additional times during the climb. With each engagement, the CAS displayed multiple caution messages. During the postaccident interview, the PIC could not recall engaging and reengaging the autopilot multiple times. Coincident with each autopilot disconnect was the manual adjustment of the horizontal stabilizer trim.

According to the CVR, at 1537:58, the SIC stated, “I’d just leave the autopilot off,” and the PIC responded with, “all right,” and “get the checklist going.” The SIC subsequently continued to mention the V-speed selections and questioned the captain on how to program the FMS. For about 4 additional minutes, the crew continued to discuss FMS programming and V-speeds, and at 1542:49, the SIC stated that, “okay there we go … they took those” to which the PIC responded, “aright… run the checklist.”

The SIC, via an electronic flight bag (EFB), located the quick reference card and the PRI STAB TRIM FAIL [Primary Stabilizer Trim Failure] checklist. The SIC reported in a postaccident interview that he selected the PRI STAB TRIM FAIL checklist because, “…it’s the only trim fail checklist in the quick reference [card] and it seemed to be the root cause of our problem.”

The SIC reported that he visually showed the PIC the checklist on the EFB, and they 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 subsequently moved the switch to the off position.

As soon as the switch position was moved, the autopilot disconnected, and with the autopilot no longer holding nose-down force on the elevator control surface, the elevator rapidly moved to neutral. Subsequently, the airplane rapidly pitched up, the PIC input nose-down column force, and the airplane pitched back down. The airplane pitched up again and the stall protection system activated. The PIC described during postaccident interviews that, “I did not expect it to pitch as rapidly as it did in either direction.” The PIC also reported that, immediately before the pitch oscillations, his left hand was on the flight controls and his right hand was guarding the right side of the flight controls.

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. The SIC reported that he believed the autopilot was off as they were completing the checklist.

During the oscillations, the CVR recorded that, at 1544:08, the SIC announced, “stab trim off” and the autopilot disconnect sound was immediately heard. Sounds consistent with items moving in the flight deck were heard and about four seconds after the upset began, the PIC stated, “turn it on… turn it on!” and an electronic voice announced “stall” multiple times. At 1544:26, after control of the airplane had been regained, the SIC stated, “we shouldn’t have had the autopilot on” and the PIC responded with, “yeah.”

Moments after the in-flight upset, the flight crew were alerted by one of the passengers that another passenger had been seriously injured. The SIC exited the flight deck to check on the passenger and to provide medical attention. He subsequently returned to his seat and informed the PIC that there was a medical emergency and that they needed to land.

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 wheel, at any point during the flight.

The flight crew informed air traffic control of the medical emergency and began a diversion to Bradley International Airport (BDL), Windsor Locks, Connecticut. The PIC did not reengage the autopilot for the remainder of the flight and landed about 17 minutes after the in-flight upset. 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, where she succumbed to her injuries later in the day.

Flight Data Recorder and Non-Volatile Memory Information

Takeoff and Climb

According to data recovered from the airplane’s FDR, no significant difference in airspeed between the left and right PFD airspeed indicators was observed in the data following the SIC’s removal of the pitot probe cover. Throughout the initial climb, multiple pilot-commanded pitch trim inputs and corresponding movements from the horizontal stabilizer were observed outside of the time the autopilot was engaged.

During the climb, the FDR data sh...