All aircraft should periodically inspect and maintain in airworthy condition to be safe to fly. Some of that maintenance is pre-scheduled. Other types of maintenance are sudden and unscheduled.
Aircraft scheduled maintenance is preventative maintenance that is performed at regular intervals. This type of maintenance based on maintenance program regular checks / inspection and these intervals can be determined based on maintenance program planning method, we can categorize scheduled aircraft maintenance to:
- Line maintenance like:
- ALC (After Landing Check).
- PDC (Pre-Departure Check).
- DC (Daily Check).
- WC (Weekly Check)
- Any other check doesn’t need hangar and could be performed as line maintenance.
- Heavy Checks.
- Progressive inspections.
- Aircraft weighing or any other maintenance activity need hangar to be performed.
Unlike the scheduled aircraft maintenance, the unscheduled aircraft maintenance occurs anytime a component / unit has malfunctioned or is suspected of malfunctioning, and by definition, this maintenance is unforeseen.
What are reasons for unscheduled maintenance?
The reasons of unscheduled aircraft maintenance are such:
- Pilot or maintenance staff finds a problem during the preflight inspection.
- An in-flight malfunction.
- Problems found during scheduled inspections / check.
How to minimize fleet unscheduled maintenance?
As business wise, aircraft operator aims to decrease the unscheduled maintenance to minimum this can be achieved by:
- Effective reliability program.
- Experienced RCB (Reliability control board) take the right decisions and follow up to measure the effectiveness and feedback.
- Update maintenance program according to operator utilization, special operation past unscheduled maintenance study, occurrence reports study and reliability to minimize fleet unscheduled maintenance.