Pre-flight check
Summary¶
The pre-flight check is the structured process run before every flight: inspect the aircraft, verify the electronics, confirm the site and the pilot are ready, and only then arm. It exists because memory is unreliable under pre-flight pressure and an airborne failure is almost always worse than a delayed takeoff. The process is built around explicit go/no-go gates — a small set of conditions that must be true to fly. Applies to any build, any firmware.
Concept¶
Why a check, not experience¶
Experienced pilots have accidents from skipped steps more often than beginners do from unfamiliarity. The check removes memory from the sequence: you execute a fixed list rather than recalling one, every time, including the hundredth flight on a build you know well.
Reference¶
Go/no-go acceptance criteria¶
These are the hard gates. If any is not met, the aircraft does not fly until it is resolved.
| Gate | Condition to fly |
|---|---|
| Position fix (if GPS-equipped) | Fix acquired before arming, per your firmware's threshold |
| Battery | Resting voltage within normal range for the pack, no swelling or deformation |
| Failsafe | Configured and, ideally, tested — not left at whatever the receiver defaulted to |
| RC link | Good link quality; transmitter powered before the aircraft |
| Structure | No visible frame or prop damage; fasteners that see load are secure |
| Airspace | Authorisation confirmed for the site and altitude |
| Pilot | Not fatigued, impaired, or distracted |
Everything else is a verification step; the gates above are what turns a no-go into a go.
Procedure¶
Standard pre-flight sequence¶
- Site: check for people, obstacles, and airspace restrictions.
- Structure: visually inspect props, arms, and any fastener that's taken load recently.
- Electronics: confirm battery voltage, confirm logging is active if you care about this flight's data, confirm RC link quality.
- Arm in an open area, clear of people and obstacles.
- If this is a new build or a build that's had recent work done: hover briefly at low altitude before committing to a normal flight, and feel the motors after landing.
Rationale¶
Why transmitter on before aircraft¶
If the aircraft is powered before the transmitter is connected, it sees no RC signal and may enter failsafe immediately. For a build with an autonomous return mode configured, this can trigger unexpected behaviour on the ground before the pilot has any control. Transmitter first ensures the RC link is established before the flight controller's control loop initialises.
Why a position fix is a hard gate when the firmware offers autonomous return¶
An autonomous return-to-home function generally can't work without a recorded home point, and the home point is typically recorded only at arm time. Arming without a fix silently disables that safety net for the whole flight. If you then lose the RC link, there's no automatic return. This is a documented cause of real incidents in FPV operations — treat the gate as non-negotiable, not advisory.
Connections¶
requires: [] related: - lipo-batteries - legal-and-regulatory leads_to: - maiden-flight