1.3 Operating Guides, Maintenance & Safe-to-Fly Decisions

The Operating Guide Is a Limit, Not a Suggestion

UAS.OPEN.060 requires the remote pilot to operate the UAS in accordance with the manufacturer’s instructions, including applicable limitations. For the A2 candidate, the operating guide is the primary source for the particular aircraft’s maximum mass and approved payloads; wind, temperature, moisture, and altitude limits; batteries; balance; propellers; control link; automated and lost-link behaviour; maintenance intervals; and emergency procedures.

A forum value, another model’s manual, or a generic checklist cannot raise a manufacturer limit. If the guide prohibits rain, an A2 CofC does not authorise rain operations. Keep the current manual accessible, and review release notes after software changes.

Scheduled Maintenance

Scheduled maintenance is work performed at the time, cycle count, or condition specified by the manufacturer or operator programme. Typical tasks include:

• inspecting and replacing propellers;
• checking motor bearings, shafts, mounts, and unusual noise;
• checking arms, hinges, landing gear, body shells, and fasteners;
• cleaning vents, cameras, obstacle sensors, and cooling paths;
• checking battery cycles, swelling, balance, connectors, and retention;
• calibrating or checking sensors only when the manufacturer calls for it;
• confirming compatible aircraft, controller, battery, and app software; and
• replacing time-limited or damaged components.

“Maintenance-free” marketing does not mean “inspection-free.” Small cracks, loose screws, contaminated connectors, or propeller damage can become loss of control after repeated vibration. Record significant work so recurring defects and battery ageing can be identified.

Unscheduled Inspection Triggers

Some events reset the safe-to-fly question immediately:

• collision, tip-over, propeller strike, or hard landing;
• water, salt spray, dust, sand, or chemical exposure;
• battery overheat, abnormal odour, swelling, or impact;
• motor, GNSS, compass, Remote ID, or control-link warning;
• unexplained vibration, drift, noise, heat, or shortened endurance;
• loose or shifted payload; and
• software update, configuration reset, or repair.

After such an event, do not merely restart and relaunch near people. Power down safely, isolate any damaged battery, inspect the whole aircraft, identify the cause, and follow the manufacturer’s return-to-service steps.

Repair Decisions

A repair is acceptable only when its parts, method, competence, and verification are suitable. Cosmetic tape over a cracked structural arm, reshaping a propeller, using an unapproved battery, or bypassing a warning is not maintenance.

Use manufacturer-approved or demonstrably suitable parts and observe orientation, torque, balance, and firmware requirements. If the guide reserves a repair for an authorised service centre, use that route. A pilot who cannot determine whether hidden damage exists must ground the aircraft.

After repair:

1. inspect the completed work and check no tools or loose parts remain;
2. verify configuration, mass, centre of gravity, and payload security;
3. power on in a controlled location and confirm warnings are clear;
4. test controls and automated functions as directed;
5. perform a short, low-risk test flight far from uninvolved people; and
6. reassess before returning to Near People work.

A successful power-up is not proof that a repaired structure or motor will withstand flight load.

Safe-to-Fly Inspection

The configured aircraft must be safe. A bare airframe within limits can become unsafe when a camera changes balance, a light obscures a sensor, or a battery pushes mass beyond a limit.

Go, Correct, or Ground

• Go: no defect, all limitations met, configuration verified.
• Correct and recheck: a resolvable item followed by full verification.
• Ground: damage, unexplained warning, out-of-limit mass, uncertain repair, swollen battery, or any condition that cannot be proved safe.

Commercial pressure does not create a fourth category.

Scenarios

Propeller nick. A blade tip struck gravel. Sanding it by eye changes balance and strength. Replace it according to the guide and inspect the motor and arm before a low-risk test.

Rain exposure. An aircraft not approved for the moisture lands after a shower. Drying the shell externally is not enough. Follow the manufacturer’s inspection process and ground it until exposure is resolved.

Firmware before a job. An update changes RTH behaviour. Review release notes, verify settings, and flight-test in a safe area rather than discovering the change beside pedestrians.

Recurring compass warning. Recalibrating repeatedly beside reinforced concrete does not prove the aircraft healthy. Move away from interference, diagnose using the guide, and do not launch until the indication is understood.

The rule is manual limits + maintained system + verified configuration = candidate for flight. If any term is missing, do not fly near people.