An inquiry has questioned whether a pilot whose light aircraft crashed and burst into flames near a south Norfolk airfield was physically and mentally fit to fly on the day of his fatal accident.

Concerns had been expressed about the airmanship of 66-year-old Pavel Sedlacek who was known to use incorrect landing techniques, used incomplete charts and flew with a lack of over-water safety equipment such as lifejackets, according to a report by the Air Accidents Investigation Branch (AAIB).

The Czech Republic national, who lived in Austria, crashed nose-down into a field at Puddleduck Farm on his way to Old Buckenham Airfield on May 9 last year where maintenance work on his Mooney M20B aircraft was scheduled to take place.

Shortly before, he had mistakenly landed at nearby Tibenham Airfield and was seen to have been in an 'agitated and distressed' state.

Investigators cannot pinpoint why Mr Sedlacek lost control of the plane, but the suspicion is that he had become briefly distracted while attempting to land. Although he had worried about the aircraft's brakes before the accident, no defects were found, although recovered documentation revealed its Certificate of Airworthiness had expired in February 2010. Mr Sedlacek gained his Private Pilot's Licence in June 2007 and bought the Mooney M20B in August 2009 but had not flown it since two months before the accident.

He left Biberach Airport, in Germany, at about 12.25pm on May 9. After requesting airfield details from Old Buckenham, he landed unexpectedly at Tibenham Airfield at about 4.30pm and spoke to members.

The report said: 'They described him as being in a highly agitated, even distressed, state. He was sweating profusely, with sweat-soaked clothing. He was also very voluble and talked of a number of things, including personal family issues which were obviously a source of concern to him.'

Club members encouraged him not to fly, but Mr Sedlacek was keen to continue. At about 5.05pm, he crashed into a field of young crops, causing the cabin area to burst into flames.

Personnel from Old Buckenham said he consistently used an incorrect technique which resulted in fast approaches and long landings.

The report concluded: 'The pilot's flying abilities and standard of airmanship appeared questionable considering the events of the accident day and reports from beforehand. The pilot's mental and physical fitness to fly were also in doubt.'