A MILITARY plane used for fast-jet training avoided a low-level mid-air collision with three model aircraft by luck, an official investigation has concluded.

The UK Airprox Board has rated the incident, which happened near the North York Moors and involved a Tucano which had flown from No 1 Flying Training School, at RAF Linton-on-Ouse, near Easingwold, as among the most serious it investigates, stating the safety of the aircraft may have been compromised.

The Tucano pilot said he was flying at 300ft at 2.20pm on September 7 last year when he was startled by seeing the model aircraft at the same altitude over Yedingham.

During a subsequent military investigation, it was concluded the model aircraft were seen too late for the Tucano pilot to take any avoiding action.

The pilot assessed that the model aircraft had wing spans of approximately one metre, which would have made any collision "quite likely to result in significant damage".

The Airprox report states: "The aircraft was climbed in order to identify the source and a well-established model aircraft flying site was identified with about seven aircraft on the ground and a number of vehicles parked. The pilot noted that it was only by chance that there had not been a collision.

"He noted that the area was regularly used for low-level training and therefore that the site posed a hazard to aircraft."

The model aircraft operator could not be traced.

The report states while their are no regulations limiting the maximum height for the operation of model aircraft that weigh 7kg or less other than if flown using a wireless video feed, model aircraft weighing between 7kg and 20kg are usually limited to 400ft.

It states: "There remains a requirement to maintain direct, unaided visual contact with the aircraft sufficient to monitor its flight path in relation to other aircraft, persons, vehicles, vessels and structures for the purpose of avoiding collisions."

The report said the military encouraged all users of the air, including model aircraft clubs, to attend local Regional Airspace User Working Groups, so that all those using the airspace understand and are aware of each other’s activities. Since the incident, the location of the club near Yedingham has been made widely known at RAF Linton on Ouse to ensure that all crews are aware of its presence.

The board concluded: "It was felt unfortunate that the board did not have the model operators’ perspective on events, but members agreed that this incident was a conflict in Class G airspace and, given the speed of the Tucano, that separation had been such that safety had been much reduced below the norm."