MYSTERY still surrounds an air crash from which crop circle maker Matthew Williams walked unscathed.

Mr Williams, 36, from Bourton Lane, Bishops Cannings, was flying his 1987 Pegasus microlight towards its landing strip near Melksham in October last year when the single engine inexplicably stopped.

Mr Williams said: "A microlight is essentially a glider with an engine so learning to fly it without an engine is all part of the training.

"I knew I would not reach the landing strip, so I looked out for a nice flat field in which to make an emergency landing.

"It turned out to be a bit steeper than I anticipated and I'm afraid I was unable to avoid the fence at the end.

"I had a passenger with me and he commented that I was quite calm about the whole thing. Apparently I said to him, sorry, I don't think we're going to miss that fence.

"And sure enough, we didn't."

Air accident investigators have been unable to find any reason why the engine of the tiny aircraft stopped.

An Air Accident Investigation Branch report published last week said that Mr Williams, who had over 100 hours' flying experience, was on a local flight from a farm strip when he encountered light rain.

It continues: "The pilot decided to return to the airfield and, in order to save time, planned to join the circuit on base leg.

"However, whilst maintaining 500ft above ground level and a typical cruise power setting of 5,000rpm, the engine cut out without warning.

"A number of fields appeared to be suitable for a forced landing and the pilot chose what he thought was the best one. The landing was slightly deep, as a result of having to avoid trees on short finals.

"Having touched down, it became apparent that the field had a downhill gradient which had not been obvious from the air. The slope, combined with the damp conditions, made it impossible for the pilot to stop the aircraft before reaching a ditch and fence on the field boundary.

"The nosewheel fell into the ditch, causing the aircraft to flip over and come to rest on the fence in an inverted attitude. Neither occupant was injured, although the aircraft sustained major damage."

The report says that an investigation by experts after the accident failed to reveal any reason for the engine failure. It had not seized and the ignition system was found to be serviceable.

Mr Williams, a self-employed web page designer, says the experience has not put him off flying and he has replaced the £2,500 aircraft, which was insured.

He said: "I was on the point of gaining my pilot's licence for larger aircraft when I lived in Wales, so when I moved here I completed my training and got my licence for microlights."

Mr Williams is probably best known as the only person in the UK to be successfully prosecuted for making crop circles.

He has since made a name for himself creating crop circles for TV companies and commercial firms and created one on the occasion of the Gazette and Herald moving to compact format.