A small remotely-piloted helicopter came within 20ft of a landing passenger jet in a disturbing incident described in a new report.
The full details of the incident that took place in the early afternoon of 22 July this year were revealed in a report by the UK Airprox Board, published today, which rated the incident as an A on a five-point scale, meaning the highest level of collision risk.
The incident was reported by the pilot of an Airbus 320 with some 180 people aboard, who spotted the small remotely piloted helicopter flying over its wing while approaching a runway at London’s Heathrow airport.
“A small black object was seen to the left of the aircraft as they passed 700ft in the descent, which passed about 20ft over the wing. It appeared to be a small radiocontrolled helicopter,” the board said in the report. “The object did not strike the aircraft and the pilot made a normal landing but it was a distraction during a critical phase of flight.”
Despite extensive investigation, the owner of the drone was never found.
The intruding aircraft wasn’t equipped with a radio transponder and thus not visible on air-traffic control radar.
The incident sparked a flurry of voices calling for tougher regulations of the booming unmanned aerial system sector as well as stricter requirements for their operators.
“The common air-traffic control radars are designed for detecting, surveying and tracking large aircraft at ranges of many hundreds if not thousands of kilometres,” Peter Doig, a defence technology consultant at Plextek Consulting told E&T.
“They are not designed to look for something like a quadcopter or a small one or two metre fixed-winged aircraft, which could comfortably fly at 700ft. These UAVs have a very small radar cross-section as they are predominantly made of non-metallic materials, such as plastics, which don’t have a very big return from radar.”
The investigators from the UK Airprox Board concluded the UAV operator deliberately chose to fly so close to the landing aircraft, causing considerable hazard to the plane, its crew and all passengers aboard.
"That the dangers associated with flying such a model in close proximity to a commercial air transport aircraft in the final stages of landing were not self-evident was a cause for considerable concern,” the report said.
"UKAB members reiterated that anyone operating an air vehicle, of whatever kind, had to do so with due consideration for regulation and for other airspace users, and preferably under the auspices of an established association or club."
The board called for the UK Civil Aviation Authority to bring the issue of remotely piloted aircraft operations to wider public attention.
Earlier this year, airline pilots' association Balpa demanded better protection for the public against the risks of drones, saying UAV operators should be obliged to undergo similar training to pilots.
So far, anyone can buy and fly a drone in the UK for as little as a few hundred pounds.
Apart from random incidents and irresponsible handling, the technology could be directly misused by terrorists who could attach explosive devices to the remotely operated aircraft with the intention to cause damage.
According to the UK Civil Aviation Authority, small unmanned aerial systems not equipped with radar transponders and thus invisible to air-traffic controllers, should be either operated within segregated airspace or within the line of sight of the operator up to a maximum altitude of 400ft.