UK – Airprox 2015046

Date: 11 Apr 2015 Time: 1525Z Position: 5118N 00007W Location: West abeam Kenley
(Saturday)

THE EC130 PILOT reports tracking to the Isle of Dogs for a London sightseeing tour. West abeam
Kenley gliding site at 1600ft QNH, he saw what he believed to be a helium party balloon about 20° off
the port side at a range of about 500m. He assessed his course would not take him near the object
so he held his heading. As the object came closer, he realised that it was in fact a drone helicopter,
shaped like the number 8. It passed down his port side at the same altitude, about 100ft away. The
passengers on the port side also saw the drone. The pilot called Heathrow Radar, reported the
incident and informed the controller that he would file an Airprox.

He assessed the risk of collision as ‘Medium’.

THE DRONE OPERATOR: The Drone Operator could not be traced.

THE LONDON TERMINAL CONTROL CENTRE CONTROLLER reports acting as Group Supervisor Airports. The Thames radar controller [Heathrow SVFR] called him to state that an EC130 pilot
wanted to file an Airprox against a drone that he had encountered, approximately 1 mile west of Kenley. The helicopter was at 1600ft at the time, and the pilot considered the drone to be at the same level, about 100ft away from him. This was outside controlled airspace.

Factual Background

The weather at Heathrow and Gatwick was recorded as follows:

METAR EGLL 111520Z 27014KT CAVOK 13/M02 Q1022 NOSIG
METAR EGKK 111520Z 26012KT CAVOK 13/M00 Q1022

Analysis and Investigation

CAA ATSI

The EC130 departed for a local flight to the north squawking 3767. Radar recording only showed
an intermittent primary contact manoeuvring 4.6nm north-northwest of Redhill. This was 2.2nm
west of the projected flight path of the EC130 and was judged not to have been the reported
drone. At 1522:33, the EC130 is shown tracking north at an altitude of 1000ft. The intermittent
contact had faded from radar, Figure 1.

Figure 1: Heathrow single source radar at 1522:33

The EC130 pilot changed to a 7000 squawk and, at 1523:08, he contacted Heathrow SVFR. A Basic Service was agreed and the EC130 pilot was instructed to squawk 7033 with QNH 1022hPa. At 1523:33, the EC130 was 3.5nm north of Redhill and the intermittent contact was shown manoeuvring in the EC130’s 10 o’clock at a distance of 2.2nm, Figure 2.

Figure 2: Heathrow single source radar at 1523:33

At 1524:22, the EC130 was 4.5nm north of Redhill at 1600ft. No other radar contacts were shown to be in the area, Figure 3.

At 1524:34, the EC130 pilot reported being passed by a drone whilst at 1600ft. The Heathrow SVFR controller was not aware of the drone and there were no other radar contacts in the area at the time of the reported Airprox. It is unlikely that a drone would be detected by area radar.

UKAB Secretariat

The Air Navigation Order 2009 (as amended) , Article 138 states:

‘A person must not recklessly or negligently cause or permit an aircraft to endanger any person or
property.’

Article 166, paragraph 2, states:

(2) The person in charge of a small unmanned aircraft may only fly the aircraft if reasonably satisfied
that the flight can safely be made.

(3) The person in charge of a small unmanned aircraft must 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.

A CAA web site provides information and guidance associated with the operation of Unmanned Aircraft Systems (UASs) and Unmanned Aerial Vehicles (UAVs). Additionally, the CAA has published a UAV Safety Notice which states the responsibilities for flying unmanned aircraft.

This includes:

‘You are responsible for avoiding collisions with other people or objects – including aircraft.

Do not fly your unmanned aircraft in any way that could endanger people or property.

It is illegal to fly your unmanned aircraft over a congested area (streets, towns and cities).

Also, stay well clear of airports and airfields’.

The CAA issued SI 2015/02 (Issue 1), AIRPROX Involving Small Unmanned Aircraft, on 8 May 2015. This is an amendment to the Airprox reporting procedure at Section 6, Chapter 3 of CA 493 (Manual of Air Traffic Services Part 1) and states that reporting action at aerodromes and ACCs is to include notification to civil police of the location of the Airprox as soon as practicable to initiate tracing action.
Summary

An Airprox was reported when an EC130 helicopter and a Drone flew into proximity at about 1525 on
Saturday 11th April 2015. The EC130 pilot was operating under VFR in VMC in the Class G airspace
of the London FIR and in receipt of a Basic Service from Heathrow Radar.

PART B: SUMMARY OF THE BOARD’S DISCUSSIONS

Information available consisted of a report from the EC130 pilot, radar photographs/video recordings,
a report from the air traffic controller involved and a report from the appropriate ATC authority. Members quickly agreed that the drone operator was probably not in direct visual contact with the drone at the altitude reported (at or above 1000ft above ground level) and had either lost control of the drone (which had then strayed in height) or was perhaps using a First Person View (FPV) system which requires a competent observer to be present in order to detect converging aircraft, (but who would be similarly hampered by difficulties in maintaining direct visual contact with the drone at such a height). It was also noted that the relevant ANO Articles (which may also be found at www.caa.co.uk/uas) state that a person in charge of a small unmanned aircraft may only fly the aircraft if reasonably satisfied that the flight can safely be made, and must 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. In short, as the CAA website states, “The operation [of the drone] must not endanger anyone or anything”. The Board opined that, in collision avoidance terms, the perception and definition of ‘endanger’ could be very different between an experienced aviator and a person with no aviation experience at all.

As for the EC130 pilot, the Board noted that he had seen the drone at range and, although under the
impression it was a balloon, had elected to continue on his course. Some members felt that it may
have been more prudent to increase separation anyway if possible (even if it had turned out to just be
a small party balloon), rather than accept reduced separation from an object in the air. Nevertheless,
it was agreed that it had been the EC130 pilot’s subsequent concern at the proximity of the drone that
had resulted in an entirely appropriate Airprox report.

Finally, the Board observed that drone operators have the same right to conduct their business or leisure activities in UK airspace, and especially so in Class G, as do other airspace users. However, after much discussion, it was agreed that the reality of current drone technology and its increasing sophistication appeared to be outstripping the regulatory framework required to ensure safe operation in a shared aviation environment.

Members agreed that drone collision was especially hard to mitigate with current legal provision, and that expressions such as ‘endanger’ were open to interpretation, especially by non-aviators who may not have an appreciation for the risks that were involved.

Ultimately, operators of drones of less than 7kg mass were required to maintain at least 50m from any third parties but, in the dynamic air-to-air case, the Board opined that judging 50m to any degree of accuracy from the ground was practically unachievable and therefore largely unworkable as a rule.

This particular Airprox had highlighted the problem with these rules, the drone may or may not have been within 50m from the EC130, and might therefore have satisfied the legal minimum, but there was no real ability to conduct that assessment even for experienced pilots.

Furthermore, the issue of who should avoid whom was not clear; the operator of a stationary drone might not be able to see an approaching aircraft in time to take meaningful avoiding action, and might well have an expectation that the other aircraft would in any case avoid his drone if it was either stationary in position and height and thus being ‘overtaken’, or was on the right-hand side of the approaching aircraft in a converging situation (SERA 3210 (Right of Way) does not mention drones specifically, so the assumption may be that they come within the classification ‘power-driven heavier than-air aircraft’, and that normal privileges apply in that respect).

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The EC130 pilot was concerned by the proximity of the Drone.

Degree of Risk: C.