RPAS Systems & Battery Safety
You don't need to be an engineer, but you must understand the parts that keep your aircraft flying — and the battery that powers them, which is the single biggest safety hazard you carry.
The core systems
- Flight controller — the "brains"; turns your inputs + sensor data into motor commands via the ESCs (electronic speed controllers).
- IMU (inertial measurement unit) — senses orientation/movement. Leave the aircraft still on a flat surface while it powers up so the IMU initialises correctly.
- GNSS / GPS — needs at least 4 satellites (most makers suggest 7+ before launch); fewer at northern latitudes.
- Magnetometer (compass) — tells the aircraft which way it points. Calibrate away from metal: ~2 m from rebar, ~15 m from vehicles, ~55 m from high-tension powerlines.
- Barometer — measures altitude; height shown is relative to your take-off point.
Battery safety (LiPo)
Lithium-polymer cells pack a lot of energy and fail dangerously if abused.
- Never charge unattended or near flammable materials.
- Keep cells above 15 °C before flight; cold cuts flight time sharply and can drop voltage suddenly. Don't charge a cold battery (below ~10 °C).
- Let a hot pack cool before charging; keep packs out of direct sun.
- A swollen or impact-damaged battery is scrap — isolate it and dispose of it properly; never fly or charge it.
A LiPo fire is fast and intense. If a pack is dropped, swells, or gets hot, stop — do not fly it. Carry a way to contain a battery fire.
In the cold, keep spare packs warm inside your jacket and warm/cool them slowly to avoid shock-heating. Track charge on every battery — aircraft, controller and tablet.
Maintenance & logs
Follow the manufacturer's maintenance program; inspect props and airframe for cracks, chips or fraying before each flight. Keep flight logs (12 months) and maintenance logs (24 months).
Check your understanding
Key takeaways
- Let the IMU initialise still; calibrate the compass away from metal.
- GNSS wants 4 satellites minimum, ~7+ before launch.
- Cold, swollen, or unattended-charging batteries are the main hazards.
- Inspect before every flight; keep flight (12 mo) and maintenance (24 mo) logs.
Sources: RPAS 101 pp.66–74 · CAR 901.78 (operating manual) · TP‑15263 §2 (Airframes & Systems).