What happened
On 11 April 2024, a Cessna T210M, registration N761JU, was attempting a takeoff from Leeds East Airport when the pilot encountered significant control difficulties. During the takeoff roll, the pilot attempted to rotate the aircraft at approximately 70 kt but found the control column resistant to movement. Deciding to abort the takeoff, the pilot closed the throttle at roughly 100 kt. However, the sudden reduction in power caused the aircraft to briefly lift off the ground.
Upon touchdown, the aircraft bounced several times. During these impacts, the nose landing gear failed, causing the aircraft to scrape along the runway and veer off the paved surface. The nosewheel strut eventually dug into the soft ground, forcing the aircraft to flip and come to rest inverted. While the pilot escaped with minor injuries, the passenger sustained fatal injuries following a severe impact to the head against the cabin roof.
The investigation
Investigators examined the aircraft' and discovered that the pitch trim was set to the full nose-down position. While the pilot had performed pre-takeoff checks and believed the trim was correctly set for takeoff, the investigation focused on how the setting changed.
Testing of the aircraft's King KFC 200 autopilot system revealed an intermittent fault within the KA 117 pitch trim adapter. This component was found to be sending a continuous trim-up command to the flight computer, which, when combined with certain autopilot modes, could result in the system driving the elevator trim electrically nose-down. The investigation also noted that the autopilot components installed were not in full accordance with the original Supplemental Type Certificate (STC).
Furthermore, the investigation reviewed the pilot's documentation, including a homemade Quick Reference Handbook. It was noted that the aircraft's official Pilot's Operating Handbook lacked specific guidance or emergency procedures regarding the autopilot's trim warning light or potential trim runaways.
Findings
- The primary cause of the accident was the attempt to take off with the aircraft pitch trim set to the full nose-down position.
- An intermittent fault in the autopilot's pitch trim adapter likely caused the uncommanded trim movement.
- The pilot was unable to detect the trim change because the movement was pulsed and the manual trim wheel was black, making visual monitoring difficult during the takeoff roll.
- The failure of the nose landing gear during the bounces was a significant factor in the aircraft's loss of directional control and subsequent inversion.
- There was a lack of specific training and instructional material regarding the management of autopilot-related trim failures in General Aviation aircraft.