Maintenance
Scheduled and unscheduled maintenance
§ 107.15 requires the aircraft to be in a condition for safe operation, but for most operations Part 107 does not prescribe how to keep it there — no maintenance schedule, no required tasks. The one exception is a Category 4 aircraft, whose maintenance, preventive maintenance, alterations, and inspections § 107.140(c) places on the owner or operator, as § 5.4 covers. The FAA’s guidance in AC 107-2A fills that in, and it describes small-UAS maintenance as falling into two kinds: scheduled and unscheduled. Neither is a Part 107 mandate on its own; both are the recommended practice for meeting the one standard that is binding. Keeping the two straight matters, because they are triggered by completely different things.
The difference is simply what sets the work in motion. Scheduled maintenance is planned in advance, against a clock or a counter, before anything has gone wrong. Unscheduled maintenance is reactive — it happens because something turned up, in a preflight check or after a hard landing. A good operator does both: follows the plan, and responds to what the plan did not foresee. What they share is the goal, which is always the § 107.15 condition for safe operation.
Scheduled maintenance
Planned work, done before anything has failed. AC 107-2A’s guidance is that the manufacturer may set time-in-service limits — flight hours, cycles, or calendar-days — for servicing or replacing components, and the operator should follow that recommended schedule.
Where the manufacturer provides no schedule, the guidance suggests the operator build one: document each repair, modification, or replacement and record the component’s time-in-service, so a reliable schedule emerges over time.
Unscheduled maintenance
Reactive work, triggered when a defect turns up outside the plan — a component found in a preflight to need servicing or repair, damage from a mishap, or a manufacturer-required software fix.
AC 107-2A’s rule of thumb is blunt: when such a condition is found, flight operations should not occur until it is corrected. The defect, not the calendar, sets the timing.
Key terms
Scheduled maintenanceUnscheduled maintenanceTime-in-serviceManufacturer instructionsMaintenance records