Airspace, flight planning and risk assessment

Most drone accidents and violations begin before take-off. A pilot who did not notice the nearby heliport, did not read the wind forecast, missed a temporary closure or never looked at where the power lines ran has already made the mistake; the flight just reveals it. Professional aerial photographers spend more time planning than flying. This lesson covers how airspace is organized, how to check it, how to read the weather information pilots use, how to survey a site and assess risk, and how to turn all of that into a written flight plan and checklist. The goal is a routine that is thorough but quick enough to use on every job.

How airspace is organized

Airspace is divided into classes that set which services air traffic control provides and what pilots must do. In both Canada and the United States, Class A is high-altitude airspace used by airliners, far above drones. Lower down, airspace around busy airports is controlled, meaning air traffic control separates aircraft and drones need authorization to enter. Away from airports, low-level airspace is usually uncontrolled, Class G, where no air traffic control service is provided and drones may fly within the rules without authorization. Between these lie areas such as control zones around smaller airports, terminal areas, and corridors used by aircraft approaching and leaving runways.

In Canada, NAV CANADA provides air navigation services. Controlled airspace near the ground includes control zones around airports with control towers, typically Class C or D, extending from the surface upward. Class E airspace also exists and may start at the surface around some airports without towers. Drones must not enter controlled airspace without the advanced certificate and a NAV CANADA authorization. There are also restricted and advisory areas, such as military ranges, national defence sites and some prisons, shown on aeronautical charts and in the Designated Airspace Handbook. Transport Canada's guidance points pilots to tools such as the NAV Drone app, which shows airspace and handles authorization requests, and the National Research Council's Drone Site Selection Tool, which displays airspace and aerodromes on a map. Aerodromes include not only airports but also heliports at hospitals, water aerodromes on lakes and small private strips, many of which are listed in the Canada Flight Supplement and Water Aerodrome Supplement.

NOTAMs and temporary restrictions

Airspace changes from day to day. NOTAMs (notices to air missions, formerly to airmen) announce closures, hazards and changes, such as a crane near an airport, a temporary restricted area around a forest fire, a military exercise or an air show. Forest fire areas in particular are restricted under the CARs, and flying a drone near a wildfire is dangerous and illegal because it can ground firefighting aircraft. NOTAMs are published by NAV CANADA and can be checked through its flight planning website and many drone apps. Pilots should check NOTAMs on the day of the flight, not just when quoting the job.

Weather for drone pilots

Weather affects safety, battery life and image quality. Key factors are wind, especially gusts; precipitation, which most drones are not sealed against; visibility and cloud base; temperature, which affects batteries and can cause icing; and light, which matters for both photography and keeping the drone in sight.

Wind is the most common limit. Wind speed usually increases with height, so a breeze of 15 km/h at the ground may be 30 km/h at 100 metres. Manufacturers list a maximum wind resistance, often around 10 to 12 m/s for small camera drones, but that is a survival figure, not a comfortable working limit. Many professionals set personal limits well below it, and lower still for precise video or mapping. Gusts are more dangerous than steady wind because they can push the drone suddenly toward obstacles and drain batteries as the aircraft fights to hold position. Flying downwind away from the launch point is risky: the return trip into the wind takes longer and uses more battery.

Pilots use aviation weather products as well as general forecasts. A METAR is a routine report of current weather at an airport; a TAF is a terminal aerodrome forecast covering the next 24 to 30 hours. Both use a compact code. Reading them at an awareness level helps a drone pilot understand wind, visibility, cloud and gusts near the job.

NAV CANADA publishes METARs and TAFs through its aviation weather website, and Environment and Climate Change Canada provides public forecasts, radar and lightning maps. In Canada, METARs give wind in knots, visibility in statute miles and temperatures in degrees Celsius, with altimeter settings in inches of mercury.

Cold weather deserves special attention. Lithium batteries lose capacity and voltage in the cold, and a battery that shows 40 percent can drop suddenly under load. Batteries should be kept warm until use, the drone should hover briefly after take-off so the battery warms, and flights should be shorter. Freezing drizzle or fog can ice propellers, which reduces lift dangerously. In hot weather, batteries and motors can overheat, and density altitude rises, so propellers produce less thrust in thin, hot air, especially at high-elevation sites.

The site survey

Canadian rules require pilots to carry out a site survey before flying, to identify hazards and confirm the operation can be done safely. The survey covers the boundaries of the operating area, the type of airspace and nearby aerodromes, the location and height of obstacles such as buildings, towers and power lines, the predicted weather, the distances to bystanders and the people likely to be present, and possible areas for emergency landing.

A survey can begin on a computer using satellite imagery, street views, airspace maps and terrain data, but it should be confirmed on arrival, because satellite images can be years old. Common surprises include new buildings or cranes, guy wires on towers, trees that have grown, and events such as markets or sports games that bring crowds. The launch and landing area should be flat, clear of people and away from metal structures that can affect the compass.

Assessing risk

Risk combines how likely something is to go wrong with how bad the result would be. A simple risk matrix scores each hazard for likelihood and severity, multiplies them and ranks the results. High scores need mitigation before flight: changing the flight path, adding a visual observer, choosing a different time, using a lighter drone, closing off an area or not flying.

For operations that need an SFOC or fall under the newer beyond-visual-line-of-sight rules, Transport Canada expects a structured risk assessment based on the Specific Operations Risk Assessment (SORA) method developed by the international JARUS group. SORA considers the ground risk, meaning who could be hurt below the flight, and the air risk, meaning the chance of encountering crewed aircraft, then assigns mitigations and a level of assurance. A photographer doing routine basic or advanced flights does not need a full SORA, but borrowing its logic of ground risk and air risk improves everyday planning.

Turning planning into a flight plan

The result of planning should be a short written plan the pilot and any crew can follow. It includes the location and coordinates, the airspace and any authorization, the date and time window, the weather limits that will cancel or pause the flight, the take-off and landing points, the planned flight paths and altitudes, the shots or mapping blocks, the battery plan, crew roles, emergency procedures and contacts, and any permissions. For mapping, the plan adds the flight lines, altitude, overlap and ground control points (lesson 8).

Checklists turn plans into consistent actions. A typical sequence uses a pre-departure checklist at the office (batteries charged, firmware updated, airspace checked, permissions in hand), an on-site checklist (site confirmed, crew briefed, take-off area clear), a pre-flight checklist (propellers, battery seated, gimbal free, home point recorded, failsafe set) and a post-flight checklist (log the flight, inspect for damage, store batteries correctly). Lesson 5 covers the flying procedures in detail.

When not to fly

Good planning sometimes ends with a decision not to fly. Reasons include wind beyond personal limits, rain, poor visibility, a temporary closure, unexpected crowds, a client pushing for an unsafe or illegal shot, or a pilot who is tired or unwell. Professionals build this possibility into contracts and schedules with weather days and rescheduling clauses (lesson 11). Clients respect a pilot who postpones safely far more than one who crashes into their building.

Many professional operators finish planning with a short crew briefing on site, even when the crew is only the pilot and one observer. The briefing covers the plan and its limits in a few minutes: the airspace and any authorization, the weather limits that will pause the flight, the take-off and landing points, the return-to-home altitude, the shots or mapping blocks in order, who watches for aircraft and people, the agreed calls, and what each person does in an emergency or if the link is lost. Saying the plan out loud often reveals gaps, such as an unassigned task or a landing spot that has filled with cars, and it gives the observer permission to speak up if something looks wrong.