GA1312

Immediately following rotation, the aircraft [an EV97] continued to pitch upward rapidly. Significant forward control inputs were required to keep the aircraft within flight envelope. Pre-flight checks indicated no obstructions or issues with trim control. In addressing the issue, it was found that the passenger seatbelt had become entangled in the trim control lever during boarding, but only compromised the control when the passenger moved during the take-off sequence. This pulled the elevator trim to its maximum deflection, forcing a significant nose up movement. The seatbelt adjuster was jammed in the trim groove and required significant force to remove. Following removal of the seatbelt from the trim control, the aircraft did not exhibit any unusual control movements and the flight continued without incident.

During pre-flight checks, the trim displayed no issues and on visual inspection it was not immediately obvious that the passenger seatbelt was fouling the controls. A physical check of seatbelts is now included in the pre-flight checks, as well as increased consideration of the trim movement. I understand that the EV97 trim is known by the CAA, or at least by AAIB – they’ve flagged it to owners a few times as being powerful if inadvertently hit, and they suspect but cannot prove that it was contributory to some loss of control incidents. I haven’t read any reports before of the seatbelt obstructing the mechanism. The trim lever is located between the seats, in the same area the seatbelt hard connections are located.