A plane which crashed near Fife Aiport last year, resulting in the death of the pilot, lost power because of water getting into the engine, investigators have said.
Nicholas Denison-Pender, 50, from Perthshire, died in the crash near Kinglassie on 23 December.
The UK's Air Accident Investigation Branch (AAIB) has published a preliminary report saying that take-off had been normal.
However it said there had been "significant water contamination" that had not been removed from the fuel system during the pre-flight inspection.
It said: "The aircraft was observed to depart from controlled flight and it struck an area of rising ground, fatally injuring the pilot."
The aircraft was based at Fife Airport, near Glenrothes, and was owned by Mr Denison-Pender.
CCTV in Kinglassie, one mile south-west, recorded the sound of an engine misfiring, followed by images of the plane crash.
A witness at the airport reported hearing a brief mayday call from the pilot.
The report said significant water contamination was present throughout the aircraft's fuel system.
Officials are continuing to investigate the cause of the water ingress.
The report said: "Given the significant volume of water recovered from the fuel system after the accident, it is possible that a full sample tube of water may have been drawn from one or more of the sump drains, and that this may have been assessed as clean fuel, rather than water."
A colleague of the pilot previously paid tribute to his "inspiring balance of passion, kindness, and intelligence".