Near Miss with Drone at Heathrow
Last week, an Airprox Report was released regarding an incident in Heathrow airspace. An airprox is the term for a situation where the pilot or air traffic controllers believe that the distance between aircraft (taking into account relative positions and speed) are such that the safety of the aircraft involved may have been compromised.
If a pilot or controller is of the opinion that the distance between aircraft as well as their relative positions and speed was such that the safety of the aircraft involved was or may have been compromised then he or she may report an Airprox. In Airprox 016/2002 for example, the separation recorded on radar between the two aircraft was 400ft vertically and 3 miles horizontally: this is hardly a ‘near miss’ in the way people generally use these words. In the judgement of the air traffic controllers who reported the event it was an Airprox and was therefore fully investigated and assessed by the Airprox Board.
This particular airprox report is interesting because it involves a British Airways passenger plane and an a unmanned aircraft.
On the 22nd of July 2014, an Airbus 320 was on short final to land at Runway 09 Left at Heathrow. The weather was clear and the visibility was good. The pilot saw a small black object as the aircraft descended past 700 feet. He described it as a small radio-controlled helicopter and said that it passed about 20 feet over his left wing.
The model helicopter did not strike the aircraft and there was no further issue, however as the report notes, it was a serious distraction at a critical level of flight. The pilot reported it immediately to Heathrow Tower who warned inbound aircraft of the unidentified object but no further sightings were made.
At 700 feet, it seems likely that the “helicopter” was a multi-rotor aircraft using GPS, which can easily be bought in any enthusiast shop.
The Airprox Board worked with the local model-flying-club but were not able to identify the unmanned aircraft nor trace the operator.
The Board members were satisfied that the A320 crew had seen a model helicopter and were of the unanimous opinion that the operator of the model had chosen to fly it in an entirely inappropriate location. 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.
A spokesman for the CAA told the BBC that the CAA had to depend on people using their common sense when they operated drones.
It seems odd to even have to point that out, but a similar event at Stockholm resulted in the operator of a drone blissfully unaware that he’d just shut down the airport.
That was just last week, when Stockholm-Bromma Airport had reports of a drone in the local area. The Swedish CAA closed the Bromma CTR for all traffic below 2000 feet which stopped all flights going into and out of the airport.
An hour later they found the man operating the drone. He was documenting the construction of a motorway and had no idea about airspace or that there were any restrictions on where he could fly his drone.
A powerful drone bought on the high street will weigh 7-10 kilograms; large enough to cause real danger to commercial aircraft. The U.S. Air Traffic Controllers Association (NATCA) has stated that reports of drones flying dangerously close to passenger aircraft is becoming a daily occurrence. The fact that they are flown at low altitudes mean that they are often interfering with aircraft on final approach, as in the Heathrow incident.
In the UK, an unmanned aircraft must remain within the line of sight of the person operating it and must not be flown within 150 metres (492 feet) of a congested area or large group of people. In the US, they may not be flown above 400 feet. Both countries have an exclusion zone around commercial airports where no unmanned aircraft can be flown without ATC permission.
Having seen the issue with lasers over the past few years, however, I suspect the issues with hobbyist drones at airports has only just begun.