Coastal Survey Flight at the Edge of the Control Zone
You are hired to fly a 4.5 kg multirotor for a coastal erosion survey along a shoreline that runs parallel to a controlled aerodrome boundary. The planned track sits 400 m outside the control zone lateral boundary but only 1.2 km from the threshold of the active runway. The aerodrome tower has cleared you to operate 'outside controlled airspace, remain clear of the zone'. Your planned altitude is 90 m AGL, and the survey line requires you to fly within 150 m of a public beach car park where people are intermittently present. Wind is 12 kt gusting 20 kt from the sea. Your observer reports a light fixed-wing aircraft on a long final that appears to be descending toward the threshold.
1. What is the primary airspace and separation concern here, and what should you do in the next 60 seconds?
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The tower clearance only addresses the control zone boundary; it does not guarantee separation from aircraft operating outside the zone on approach. An aircraft on long final 1.2 km from the threshold may be below 90 m AGL and could pass close to or over your survey line. The correct action is to treat the clearance as a boundary condition, not a separation service:
- Stop the survey track and hold position clear of the extended approach path (or land if the geometry is uncertain).
- Visually acquire the aircraft, estimate its height and track, and keep your RPAS below and well clear of it.
- Re-establish contact with the tower to confirm whether the approach path crosses your operating area and whether a temporary restriction applies.
Do not assume that being 400 m outside the zone makes you deconflicted from arriving traffic.
2. Does the presence of people at the car park change your legal basis to fly, and how does the wind affect that assessment?
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Yes. Flying within 150 m of people who are not under your control engages the separation-from-people rules for your category and weight. The car park is a public area, so the people there are not 'under your control'. You must either keep the required horizontal distance from them or ensure the operation is conducted so that they are not exposed to undue hazard.
The gusting wind matters because it reduces your ability to hold a precise track and increases the chance of drift toward the car park or the beach. With 12 kt gusting 20 kt, you should:
- Widen the stand-off distance from the car park beyond the minimum.
- Re-plan the survey line so the closest point of approach to people is on the upwind side.
- Consider postponing the segment until gusts subside if you cannot guarantee the stand-off.
3. If the aircraft on final reports a go-around and climbs toward your altitude, what is your decision hierarchy?
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Priority order: see-and-avoid first, then altitude separation, then abort. A climbing go-around can rapidly enter your band, and the pilot is unlikely to see a 4.5 kg multirotor.
- Immediately descend (if the area below is clear) or move laterally away from the extended centreline.
- Do not climb to 'get above' the traffic; that shortens the vertical gap and puts you in the pilot's likely scan.
- If the conflict is unresolved, land or move to a pre-briefed safe area away from the approach path.
- Report the conflict to the tower and do not resume until you have positive confirmation that the approach path is clear.
See-and-avoid is your responsibility outside controlled airspace; the tower's clearance does not transfer it.