A pilot who crash-landed his light aircraft in a ploughed field in west Norfolk was probably forced down because the engine's carburettor iced up, according to a report out yesterday.

A pilot who crash-landed his light aircraft in a ploughed field in west Norfolk was probably forced down because the engine's carburettor iced up, according to a report out yesterday.

The man, who has not been named, made an emergency landing in Fring, near Docking, at Hunters Bells on February 20.

He walked away unhurt even though the 1985 Slingsby aircraft ended up upside down.

The pilot, 34, with 1,430 hours' experience and a member of the Pathfinder Flying Club based at RAF Wyton, Huntingdon, had taken off for a three-hour navigation exercise.

A report by the Air Accident Investigation Branch says he was flying at about 1,100ft when he noticed a loss of engine power and began to lose height.

The accident investigator says that on the day of the crash there would have been a serious risk of carburettor icing and points out: "The gradual reduction in power described by the pilot is symptomatic of carburettor icing."