Aircraft Maintenance
Aircraft Maintenance
This domain tests the nature of maintenance work, how it is classified, and how it is released. It links technical tasks to the legal chain of airworthiness directives, approved data and records.
Scheduled and unscheduled maintenance
Scheduled maintenance includes line checks (transit, daily, weekly) and base checks (often described as A, B, C and D checks). Unscheduled maintenance covers defects, AOG repairs and component replacement. Maintenance includes inspection, repair, overhaul, modification and replacement.
Directives and data
Airworthiness Directives (ADs) are mandatory; they must be accomplished within the stated compliance time. Service Bulletins (SBs) are manufacturer recommendations and are normally advisory unless an AD, operator requirement or approved maintenance programme makes them mandatory. Work must use current approved data.
Worked example
A fuel pump is replaced and the technician notices an SB for the pump has not been accomplished. The SB is advisory, so it does not automatically block release. But if an AD covers the same modification, or the approved maintenance programme requires it, it must be done before the CRS is issued. Always check the AD first.
Traps
Treating every SB as mandatory is a common error. Signing a CRS before all required tasks and inspections are complete is invalid. Do not use unapproved parts or data. Do not confuse a repair with a modification that needs design approval.