Sheer luck helped prevent mid-air drone glider prang in Blighty

Errant UAV missed aircraft on final approach by 15ft

Martin's glider on final approach
A glider pictured on finals, at a similar stage of flight as the aircraft involved in the Dunstable airprox

A drone being flown next to an active airfield on New Year’s Day caused a serious risk of an in-flight collision with a glider trying to land, the UK Airprox Board has ruled.

The drone, flying above Dunstable, a market town 50km north of London, came within 4.5m (15 feet) of the glider as it was completing its circuit and making its final turn to land. In his Airprox report, the glider pilot said the drone “was grey in colour and therefore difficult to see in the overcast weather against a backdrop of Dunstable town”.

The drone, which the pilot spotted at 550ft (167m) immediately before his turn onto finals, passed “rapidly to the right” of his glider, staying “a few metres below”. Being on finals means the glider was a few tens of seconds from touchdown.

Ominously, “there was no time to take avoiding action,” with the board spelling it out: “Had the drone been on a collision course it was unlikely that the glider would have responded to control inputs rapidly enough to allow avoiding action to be effective.”

The incident was given a collision risk rating of A, the highest available.

Dunstable Downs Airfield, home to the London Gliding Club and situated at the base of the ancient Dunstable Downs, has been a gliding site for nearly 90 years. Strong winds driving up the bowl formed by the old chalk downs have long been known to form perfect conditions for soaring flight.

At the top of the downs, a few hundred feet above the airfield, is a National Trust viewing point and car park (see a 360˚ Google Maps image here). The downs, a few kilometres west of Luton in eastern England, are a well-known tourist attraction offering beautiful views across the rolling fields of southern Bedfordshire, as well as some gentle walks across ancient chalk barrows.

Children and stunt performers alike normally fly kites near the car park and it is well understood by all concerned that gliders at the top of the ridge will stay above typical kite height. Hang-gliders can usually be seen launching from the farther reaches of the bowl on warmer days.

It is illegal to fly a drone more than 400 feet (120m) above ground level, or within 50 metres of buildings or gatherings of people. An EU agency has suggested new rules that will make it mandatory to register even hobby-sized drones with the government, which is being reflected in Britain’s Drone Bill, due for Parliamentary publication later this year. ®

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