A former RAF pilot who was teaching a 15-year-old air cadet to fly, had a rare spinal condition which may have led to both their deaths, an inquest heard.
Flight Lieutenant Michael Blee had such a stiff back he may not have been able to turn and spot a glider moments before they fatally collided in mid-air.
Schoolboy Nick Rice and Mr Blee both died when the plane they were flying in crashed into the fibreglass glider.
The pair were both killed instantly as their Grob tutor training plane nose-dived into a field as the glider pilot, Albert Freeborn, managed to eject from his engineless aircraft and escape by parachute.
An inquest into the duo's death heard how 62-year-old Mr Blee suffered from a chronic bone condition which could have made it difficult for him to raise his head and spot the glider which had been flying above his plane.
The condition, Ankylosing Spondylitis or bamboo spine, meant that the bones in his vertebrae had become fused together, limiting his mobility and potentially reducing his ability to spot other aircraft around him.
"If it affects the neck and upper part of the body it can reduce the ability to turn the head or raise the head in a nodding fashion," said Home Office Pathologist Dr Kenneth Shorrock.
He told the inquest jury in Oxford that Flt. Lieut. Blee had broken his neck during the crash, which would have killed him instantly and could have happened in the initial impact from the glider crash.
The pathologoist added that his condition would have meant his spine was less flexible than that of 15-year-old Nick, who suffered largely similar injuries as Mr Blee but had not broken his spine.
Dr Shorrock said that both Mr Blee and Nick had suffered multiple injuries in the horror crash near Drayton, Oxon., - many of which could have been responsible for their deaths.
Paramedics had raced to the scene but had been unable to access the pair until the site had been made safe, although Dr Shorrock said there would have been nothing that anyone could have done for them.
"By the time that the aircraft hit the ground there was no possibility that any medical intervention could have saved them," he said.
Nick was a pupil at the £9,060 pounds-a-year Elvian School in Reading, Berks., and had been taking part in a flying experience with Flt. Lieut. Blee along with other cadets from his school.
Glider pilot Mr Freeborn told the jury that the first he knew of the imminent crash was when he heard the roaring sound of a propeller approaching.
He soon realised that the sound was coming from underneath his own aircraft and tried his best to get out of the way of the oncoming plane.
"If you hear the sound of a propeller it's very audible and quite alarming because you know it has to be close," said Mr Freeborn, a qualified gliding instructor.
"I was travelling in a north eastern direction when I became aware of the sound of a propeller which concerned me.
"I looked left and down and I was visually aware of the plane which was very, very close beneath me."
Mr Freeborn tried to manoeuvre his glider upwards to avoid a crash but was clipped by the plane.
He managed to free himself and evacuate using a parachute, landing in a nearby field as both aircraft fell out of the sky.
Mr Freeborn, from Lee-on-Solent, Hants., said that both aircraft had been in open airspace and that there was no need for him to inform any authorities of his whereabouts.
He said that he had anticipated the skies being busy as he set off from Lasham Glider Club, near Basingstoke, Hants., but as an experienced glider pilot knew to keep a look out for anything else in the sky.
When asked if the plane's pilot would have spotted his glider had he looked up, Mr Freeborn replied: "I would have hoped so", and said that he had assumed Mr Blee, of St Mary's Green, Abingdon, had been attempting to perform a loop prior to the fatal crash.
The hearing continues.
