A mid-air disaster in the skies above Doncaster involving a helicopter and an ultra-light aircraft was only narrowly avoided.
An investigation revealed the chopper flew a short distance above the wing of a powered paraglider - a manoeuvre which can lead to a crash with ‘possible fatal results’.
A report to the UK Airprox Board, which probes air safety incidents, said the move caused a down draft disturbance to the paramotor, an incident which has been known to cause sudden loss of altitude.
The incident took place 10 miles north of Doncaster Airport.
A Eurocopter, on a private flight with a passenger, had taken off from a site in Edenthorpe, while a paramotor took flight a short distance away from Wormley Hill.
The paramotor pilot became aware of a ‘fast moving shadow approaching rapidly from behind’.
Another pilot on the ground issued a radio message warning about the approaching chopper, which then flew about 200ft above the right wing of the paramotor.
The paramotor pilot, who was on a training flight, reported a ‘slight disturbance similar to that encountered in a thermal gust, and braced himself for a sudden deflation, however the wing remained stable’.
He was concerned the helicopter pilot had ‘either not seen the brightly coloured wings on a clear day or had not altered his flight path to take avoiding action’.
The report warned: “The consequences of helicopter down draft affecting flexible paraglider wings would be rapid collapse of the wing with possible fatal results, especially at low level where deployment of an emergency parachute may not be successful.”
It added air space controllers would not have been able to warn the helicopter pilot about the paramotor’s proximity as such aircraft do not show up on radar displays.
The incident, which took place in the afternoon on March 11 last year, happened in Class G airspace, where the pilots had an ‘equal and shared responsibilty to see and avoid each other’.
An onlooker took a photograph of the incident from the ground, but a spokesman for the Civil Aviation Authority said they were unable to release the picture as it is no longer in their possession.
Board members summarised the helicopter pilot should have put more distance between himself and the paramotor.
The report concluded: “Several members thought that the vertical separation extant was adequate and the incident had been a ‘normal’ operation with no risk attached. The same number, five, thought that, although had been no risk of collision, some horizontal separation should have been afforded by the helicopter pilot to positively ensure safety.
“The chairman agreed with the latter view.”