Describe unscheduled maintenance.

• A. A routine daily check
• B. A major overhaul every 5 years
• C. Maintenance performed as the technician corrects discrepancies found during flight, walk-around inspections, schedules inspections, while performing Airworthiness Directives
• D. A minor cosmetic repair

Answer: (C)

Unscheduled maintenance is corrective work done to fix a defect or discrepancy that isn’t on the planned maintenance schedule. It happens when something is found or fails during flight, during a walk-around or other inspection, or while following Airworthiness Directives, and it must be addressed to maintain safe operation. This is different from routine preventive tasks or fixed-interval overhauls, which are planned in advance. For example, repairing a обнаруженный discrepancy discovered during a preflight check or in response to an AD is unscheduled maintenance. Routine daily checks and a major overhaul every five years are planned, scheduled activities, and cosmetic repairs, while they may occur, do not define unscheduled maintenance as their primary purpose.