14.7 Operating Near Aerodromes and Above 400 ft AGL

Why Aerodromes Concentrate the Risk

Aerodromes are where crewed aircraft are lowest, slowest and least able to manoeuvre. An aircraft on final approach is descending through the exact altitude band an RPA occupies, is committed to a path, and has no ability to see or avoid a small drone. That is why Part 101 draws no-fly zones around aerodromes and why RKOP makes this a priority-A topic.

The Vocabulary

• An aerodrome, per section 3 of the Civil Aviation Act 1988, is an area of land or water — including buildings, installations and equipment — authorised for use for the arrival, departure or movement of aircraft.
• A controlled aerodrome has an active air traffic control tower. An aerodrome without a tower, or with a tower that is not staffed, is a non-controlled aerodrome.
• A helicopter landing site (HLS) is an aerodrome intended to be used wholly by helicopters.
• The movement area is the runways, taxiways, manoeuvring areas and aprons — the ground on which aircraft move.
• The approach and departure paths are the airspace corridors aircraft use to arrive and leave. They extend well beyond the aerodrome boundary and they are the part most often overlooked.

Finding the aerodromes

AC 101-01 warns that not all aerodromes are marked on aeronautical charts, and some do not appear in ERSA. Certified aerodromes and many uncertified ones are charted, with details in ERSA, and CASA-verified drone safety apps display aerodrome areas. But a private strip on a farm may appear in none of them. The AC's advice is to also check satellite imagery or seek local knowledge for any nearby aerodrome. That is a real operational habit, not a formality: an unmarked agricultural strip beside a survey site is exactly the kind of hazard the charts will not warn you about.

The No-Fly Zones

All aerodromes have a no-fly zone. Its exact shape depends on whether the aerodrome is controlled and whether it has runways or an HLS, and the dimensioned diagrams are in Appendix A of AC 101-01.

At a controlled aerodrome, an excluded RPA must not be operated:

• over or in the approach or departure path;
• over the movement area; or
• within 5.5 km of the measurement point of the runway.

Micro RPA (250 g or less) get a concession: they may fly within 5.5 km of the measurement point up to 45 m height, provided they stay out of the movement area, out of the approach and departure paths, outside the aerodrome boundary, and create no collision hazard.

At a non-controlled aerodrome, the rule turns on activity rather than geography. Operations in the no-fly zone are permitted when there is no relevant event occurring. A relevant event is any time a crewed aircraft is within the relevant airspace — including approaching, landing at, taking off from, or manoeuvring on the movement area of the aerodrome.

The obligations that follow are precise and examinable:

• If the remote pilot becomes aware that a relevant event is occurring or is about to occur, they must not launch.
• If the RPA is already airborne, the pilot must safely manoeuvre the RPA away from the path of the crewed aircraft and land as soon as safely possible.

In plain terms: near a non-controlled aerodrome you may operate while nothing is flying, and the moment an aircraft begins to taxi for departure or appears on approach, you get out of the way and land.

Determining the Runway in Use and Traffic Patterns

Schedule 4 asks the pilot to be able to determine the runway or runways in use and to know traffic patterns at aerodromes.

The runway in use is normally the one most closely aligned into wind, because aircraft take off and land into wind. Ways to determine it:

• Listen on the CTAF or the ATIS — pilots broadcast the runway they are using.
• Read the wind — a windsock at the aerodrome, or the surface wind from a METAR or a local observation, indicates which runway is favoured.
• Watch — if aircraft are operating, observe which direction they are approaching and departing.
• Check ERSA for the aerodrome's preferred and noise-abatement runways, which can override the pure wind logic.

Traffic patterns. A standard circuit at an Australian non-controlled aerodrome is flown at 1,000 ft above aerodrome elevation for most aircraft, with left-hand turns unless the aerodrome is nominated as right-hand in ERSA. The circuit legs are upwind, crosswind, downwind, base and final. What matters to a remote pilot is not flying the circuit but knowing where the aircraft will be: on final and on departure they are low, aligned with the runway centreline, and extending several kilometres from the threshold.

Where the aerodrome has more than one runway, the picture is more complex: approach and departure paths radiate in more directions, the runway in use may change with the wind during your operation, and the combined no-fly geometry is wider than a single-runway aerodrome. AC 101-01 flags this explicitly as an additional limitation to consider.

Getting Approval

Operations in an aerodrome no-fly zone require approval.

• Non-controlled aerodrome, during a relevant event: permitted without CASA approval only if the operation is exclusively indoors (as defined in Section 1.04 of the Part 101 MOS) or a tethered operation meeting Section 9.05 of the MOS. Anything else needs specific CASA approval via Form 101-09, and CASA expects the applicant to have liaised with the aerodrome operator and identified mitigations.
• Controlled aerodrome: approval is required from both CASA and the relevant air navigation service provider — Airservices Australia for civil airspace, Defence for military. For an Airservices aerodrome, apply to CASA using Form 101-09, ideally at least 60 days ahead. For a Defence aerodrome, apply directly to Defence unless the operation is also above 400 ft AGL; instrument CASA 23/23 provides the CASA component where its conditions are met.
• Automated airspace authorisations trial: some controlled aerodromes participate, allowing application through a CASA-verified drone safety app with near real-time approval. Form 101-09 does not apply to trial flights — but the trial cannot authorise operations above 400 ft AGL.

Operators working in a no-fly zone are expected to have appropriate content in their documented practices and procedures covering the procedures and risk mitigators.

Above 400 ft AGL

Schedule 4 topic 9 asks what to consider when operating above the 400 ft height limit, and lists five things.

1. Airspace classification. Below 400 ft you may be in Class G, or in controlled airspace where CASR permits operation below 400 ft without approval. Above 400 ft you must resolve exactly which class you are entering, and controlled airspace requires clearance.
2. Aeronautical radio use and qualifications. Higher operations are more likely to require radio, and transmitting requires an AROC or equivalent. CASR 101.285 requires a radio qualification for RPA over 2 kg operating in controlled airspace.
3. Identifying the location of non-controlled aerodromes. Circuit traffic at 1,000 ft above aerodrome elevation is exactly the band you are climbing into. Identify every aerodrome and HLS within a sensible radius.
4. Use of RPA observers. An observer dedicated to scanning for crewed traffic becomes far more valuable when you are inside the altitude band that traffic uses.
5. The approval process. Included operators apply via Form 101-09, and CASA expects a review of local aviation traffic with appropriate mitigators.

One further planning point from AC 101-01: operating at height increases the ground hazard area. In strong wind, a failed RPA travels much further horizontally before reaching the ground, so the area that must be kept clear grows with altitude.