A man who died in a plane crash at Caernarfon Airport may have struggled with a fault in the flight control system, an investigation has found.
John Backhouse, 62, from Cheshire, was flying in his twin-engine plane from Northwich to Dublin when the crash happened on 6 September 2017.
Mr Backhouse contacted air traffic control five minutes before the crash requesting a diversion to Caernarfon.
Tests found it would have taken "substantial effort" to stay in flight.
The Air Accident Investigation Branch (AAIB) said Mr Backhouse was struggling with a pitch control problem with the elevators after requesting a diversion to Caernarfon.
Pitch relates to the angle between the nose and tail of the plane.
Eyewitnesses said they saw the plane approaching the runway at high speed.
CCTV footage showed the wings were level but the landing gear was retracted and the flight path had a very steep descent rate.
The aircraft broke up and caught fire after crashing into the runway, with the main part of the wreckage coming to rest 293m (961ft) further on.
The AAIB investigation examined whether or not Mr Backhouse had faced a runaway fault within the pitch trim system which was connected to the autopilot controls of the plane.
The report concluded that the fire damage made it difficult to determine the cause of the accident with a high level of confidence, but it was possible that there was a "nose-down trim runaway that the pilot was unable to stop".
John Backhouse was an experienced and highly qualified pilot who had flown a variety of aircraft and helicopters.
He was a businessman with expertise in finance and tax who had served as a Conservative councillor in Liverpool.