13.2 Site Survey, Bystander Management, Emergencies and Giving Way

Site Survey and Hazard Identification

Before any flight, the remote pilot must conduct a site survey — a systematic reconnaissance of the operating area to identify every hazard that could affect the flight. The survey can be done on-site (a physical walk before takeoff) or, for pre-planning, remotely using maps, satellite imagery, charts, and apps. The on-site walk is the authoritative one: imagery may be out of date, and a tree that was not there in last year's satellite photo may be there now.

What the site survey looks for

• Powerlines and cables — the single most common RPAS strike hazard; hard to see from the air and lethal to touch.
• Trees and vegetation — grow into flight paths, block emergency landing options, and create turbulence on the lee side.
• Buildings and structures — obstacles, wind rotors behind tall structures, and glass that reflects light and disorientates the pilot.
• Terrain — slopes, drop-offs, and uneven ground that affect takeoff, landing, and forced-landing options.
• People and animals — bystanders, children, dogs, livestock; all are unpredictable and must be kept clear of the operating area.
• Other airspace users — manned aircraft, other drones, nearby aerodromes or helipads, and any temporary airspace restrictions.
• RF (radio frequency) interference — communications towers, high-voltage lines, and industrial sites that can degrade your command-and-control link or GPS.
• Forced-landing options — clear, flat, unpopulated areas along the planned route where you could land in an emergency.
• Weather and sun angle — wind speed and direction at ground and altitude, gusts, precipitation, and low sun that blinds the pilot or camera.

Pre-flight hazard checklist

Run this at the site before takeoff, in addition to the aircraft checks:

1. Walk the area — confirm hazards match your pre-flight plan and note anything new since the imagery was captured.
2. Identify powerlines — trace their path and mark the crossing points on your route.
3. Map forced-landing spots — pick at least one clear, flat, unpopulated option along the route.
4. Check airspace — confirm no temporary restrictions and no manned traffic expected in the area.
5. Assess weather — wind at ground and altitude, gusts, precipitation, sun angle.
6. Scan for RF sources — towers, high-voltage lines, industrial emitters that could affect the link or GPS.
7. Confirm comms — control link stable, GPS lock solid, RTH set to the correct home point.

Bystander Management and the Exclusion Zone

People on the ground are the most important hazard to manage because they are the ones who get hurt. The standard control is the exclusion zone — a defined area around the operating point and under the flight path that bystanders must not enter.

• For a Standard Operating Category (SOC) operation, the default exclusion zone is at least 30 m from people not directly involved in the operation.
• Use marshals (crew members tasked with keeping people clear) and signage where the public may approach.
• Brief the crew on who calls the abort if a person or animal enters the zone.
• Never assume bystanders understand the risk — children and dogs will run toward a drone out of curiosity, and a landing drone is still spinning its props.

The exclusion zone is an administrative control, so combine it with higher-level controls where possible: route the flight away from people (eliminate), and keep the aircraft where a failure still lands it inside the zone.

Emergency and Forced-Landing Procedures

Emergencies are not predictable, but your response to them must be. The rule is to define your contingencies before takeoff, not invent them while the drone is falling.

Common RPAS emergencies

• Link loss — the command-and-control link drops. Pre-configure the failsafe: Return-to-Home (RTH), hover, or land in place, depending on the aircraft and environment. Know which mode your aircraft is set to before takeoff.
• Motor failure — a motor stops. A multirotor may spin or drop; fly toward a pre-selected forced-landing site and land immediately.
• Battery emergency — voltage drops faster than expected. Abort the mission, fly to the nearest safe landing point, and land.
• Flyaway — the aircraft stops responding and flies off. Note the last known position, attempt to regain the link, and be ready to report to ATC or police if it enters controlled airspace or crosses a road.

Forced-landing sites

Before takeoff, pre-select forced-landing sites along the planned route — clear, flat, and unpopulated areas where you can put the aircraft down if something fails. The principle is that at every point along the route, you have a place to land that does not hurt anyone. Never fly over people in an emergency you cannot control — land it in a tree or an empty paddock rather than risk dropping it on a road, a house, or a crowd. The forced-landing decision is made before the flight, not during it.

Giving Way to Manned Aircraft

CASA's rule is unequivocal: an RPA must give way to manned aircraft. Drones are the lowest-priority users of the airspace, and a manned aircraft always has right of way.

If a manned aircraft appears in your operating area — a light aircraft, a helicopter, a rescue or police flight — the correct response is to land immediately or manoeuvre clear and reduce altitude so you are well below its flight path. Do not assume the manned pilot has seen you; they almost certainly have not. Maintain visual line of sight (VLOS) at all times so you can detect manned traffic early, and brief a spotter to call out any aircraft they see.

The same principle applies to other drones on the site: coordinate with any other RPAS operator, and never assume your link or GPS is more reliable than theirs. The smallest, lowest, and slowest aircraft yields — and that is always the drone.