Four men were killed in mid-air crash between a light plane and helicopter, ...

An elderly pilot and three other men died after a collision between a helicopter and a light plane over a stately home, a coroner heard.  

Vietnamese military officer Nguyen Thanh Trung, 32, was receiving flying training with veteran instructor Captain Michael Green, 74, in a Guimbal Cabri G2 helicopter in Buckinghamshire.

But just a quarter of an hour after take off they were dramatically struck by a Cessna 152 plane piloted by 27-year-old Jaspal Bahra. 

He had been giving Savaan Mundae, 18, a flying lesson before they clipped the tail of the helicopter which led to both aircrafts plummeting 1,000ft.

Mr Mundae, who was a student at Bucks New University was studying air transport and commercial pilot training. 

The aircraft crashed near Waddesdon Manor, a Grade 1 listed building near Aylesbury in Bucks, on 17 November 2017, a jury of eight women and three men at Beaconsfield was told. 

At the start of the hearing Senior Buckinghamshire Coroner Crispin Butler said that at 11.45am the helicopter had taken off from Wycombe Park airfield about 20 miles from the crash site.  

While the helicopter took to the air at 11.45am the plane quickly followed just a minute later.

And despite both occupying the same airspace an investigation by The Air Accidents Investigation Branch (AAIB) found they were not in each others 'field of view'.

The report, published one year after the crash read: 'The opportunity for the occupants of either aircraft to see the other was limited because, although they were in proximity for some time, they were both following a similar track and were not in each other's field of view.'

This lack of visibility meant that just 15 minutes later, at 12.00pm, all four men were killed by the impact of the crash which led to 'lots of debris falling to the floor', according to witness Rupert Hill.

The jury heard Mr Hill had been out pigeon shooting at the time of the collision.

He described the horrific moment he watched the shower of debris plummeting down from the sky.

'My attention was drawn to something in the sky but I could see lots of debris falling to the floor and the sound of an engine revving to the max. I would say I was looking at this from one to one-and-a half miles away.

'It was not a helicopter, but the main body of the plane - along with all of this, I saw another aircraft, a helicopter. All of this lasted around 20 to 30 seconds, and I heard the powerful engine noise stop.

'While heading towards the crash scene I got a call from a friend. I told him what I had seen and he told me to call the emergency services.'

It was previously thought the crash was caused when the Cessna suddenly dropped in height and hit the tail of the helicopter over the Waddesdon Estate - the former country seat of the Rothschild banking dynasty. 

Giving evidence to the coroner, Home Office forensic pathologist Alexander Kolar told the hearing that all four of the deceased had suffered multiple severe injuries in the crash and offered causes of death of multiple injuries for each.

He said to the inquest jury: 'My role is the investigation of sudden deaths and interpreting injuries.'

Of Mr Mundae and Mr Bahra, who had been piloting the plane, he said: 'So this is the first case. In terms of my conclusions.... this man (Mr Mundae) has died as a result of multiple injuries, widespread non-survivable blunt force injuries and the injuries he has are very severe - almost extreme force.

'The types of injuries suggest he died extremely rapidly and there was limited bruising. I simply can't see two patterns of injuries across the collision and on impact falling to the ground.'

He offered causes of death of multiple injuries for each victim in the collision and explained the 'unsurvivable' wounds were severe to the point of extreme and noted examination of the brain, heart and other organs had ruled out the potential of natural causes contributing to, or causing, the mid-air collision. 

And he found 'fur' in one of the coronary arteries of Mr Mundae adding. He said: 'All I can say is it puts a potential medical explanation for an individual to lose control of an aircraft. It is a possibility.'

Dr Kolar said there were levels of 24 per cent carbon monoxide in the body of Jaspal Bahra. He said a normal level would be three per cent, with it being ten per cent in smokers. He said he could not tell the source of the reading from the result.

Captain Green had a level of ten per cent reading of carbon monoxide in his body, he said. 

Both he and Captain Nguyen suffered significant heat damage to their bodies but there was no evidence that they were alive when this happened.

Friends of Captain Green said his death would leave a 'gaping hole' in the commercial helicopter industry as he was one of Britain's most experienced and talented pilots. 

At the time of his death a former colleague, Captain Phil Croucher, said: 'I shared a cup of tea with him only on Thursday morning. He was a true gentleman. He was probably the most well-respected instructor in the country. He achieved a very high position within the Army as an instructor.

'He was an absolutely dedicated instructor. If you wanted a training instructor there's no one more highly qualified. Almost everybody in the country has been instructed by him. Most instructors have been trained by him.' 

Mr Croucher said claims on a pilot forum by an air traffic controller who said he saw the aircraft disappear on radar suggested the two had collided accidentally.