A pilot who fatally crashed his plane into a nature reserve in bad weather had been flying at least 1,200ft below the safe zone before the tragic incident, a report has found.

David Norris, 64, died on January 15 when his light aircraft crashed in Aston Rowant Nature Reserve, near Stokenchurch, as he was on his way from Turweston Airfield to Chalgrove Airfield to pick up two passengers.

A report released by the government's Air Accidents Investigation Branch (AAIB) said that Mr Norris had been flying below 1,000ft in an area where the Minimum Safe Altitude (MSA) was 2,200ft, for at least one minute and 45 seconds before he crashed into some trees on a high ridge.

Witnesses who were near the beauty spot – which is popular with walkers and pet owners – at the time of the accident said the weather was “foggy and miserable” and had only seen the shadow of the aircraft because of the terrible conditions.

Noises from the aircraft were heard twice with a gap of around two minutes, as if the pilot had “doubled back”.

He flew past Chalgrove Airfield at about 2.30pm and turned left towards the high grounds of the Chilterns, striking tree tops minutes later and crashing to the ground. The plane was completely destroyed.

Following the crash, a police helicopter from NPAS Benson was sent to the scene but was unable to reach the accident site for around half an hour afterwards because of low cloud.

Mr Norris, who had served as chairman of Newton Longville Parish Council in Milton Keynes for several years, had 10,673 hours flying experience, with more than 2,000 of those in the plane he was flying on the day of his death – a Piper PA-30 Twin Comanche.

The AAIB discussed potential reasons why Mr Norris was flying so low, from the stress of the conditions to an impression that visibility was better than it actually was.

But its report concluded that it was “not possible to determine whether any of them were applicable”, adding: “Shortly after reaching 2,000ft, the aircraft descended to approximately 1,000ft and, at a point where a right turn would have been appropriate for a visual approach to its destination, turned left towards high ground which was in cloud.

"The damage to the aircraft was such that the accident was not considered to be survivable. No evidence was found that the aircraft was subject to a technical failure which could have contributed to this accident."