The crew reported that the autopilot would not disengage during the approach for a night landing at Guernsey in a strong crosswind. A manually flown go-around was initiated from low altitude and the newly-qualified co-pilot, who was Pilot Flying (PF), reported the aircraft then exhibited a strong pitch-up tendency. The commander also sensed excessive pitch-up and pushed forward on his control column to assist. Thereafter the crew were alerted to activation of the Standby Control System (SCS) with the left and right elevators operating in split control.
During the go-around, the elevator control system problems distracted the crew so they did not follow the-standard go-around procedure resulting in late retraction of the gear and flaps. After levelling, the pilots realised the autopilot was not engaged and immediately re engaged it. The appropriate drill for SCS engagement was then actioned and they diverted to Jersey.
On completion of the flight, the crew reported the problems encountered to the operator and their engineers began system checks. It was not understood by the crew or those working on the aircraft that the event was a reportable serious incident and consequently, the Cockpit Voice Recording (CVR) of the event was not preserved and certain autopilot components were removed from the aircraft prior to the AAIB being notified on the evening of 27 January 2016.
Recorded flight data indicated the autopilot disengaged during the approach to Guernsey and examination of the aircraft revealed no technical defects that would have caused the incident. As the CVR was unavailable, it was not possible to ascertain if an audio autopilot disengagement alert was generated. Some human factors were identified which may have contributed to the incident. The operator has made changes to its training policies and its guidance concerning post-incident or accident response.