Aircraft Airworthiness and Maintenance Standards
What the exam tests
This domain tests continuing airworthiness from the flight engineer's side of the flight deck: the certificate of airworthiness, approved maintenance programmes, airworthiness directives, defect control, the MEL and CDL, mass and balance, and release to service. You must know what the FE may accept, what must be rectified, and what must be recorded.
Core rules
- A certificate of airworthiness remains valid only while the aircraft is maintained under an approved programme and complies with applicable airworthiness directives and limitations.
- Service bulletins are not automatically mandatory; airworthiness directives are.
- The MEL allows dispatch with specified defects only within its conditions and time limits. The CDL covers missing or altered external items.
- Every defect must be entered in the technical log; release to service follows rectification or an approved deferral.
- Preflight duties include inspection, fuel quality and quantity checks, and confirming that the load sheet and mass and balance are valid.
Worked example
Maximum take-off mass is 70,000 kg, maximum landing mass 65,000 kg and maximum zero-fuel mass 52,000 kg. Dry operating mass is 40,000 kg and payload 12,000 kg, so zero-fuel mass is 52,000 kg - exactly at the limit. Take-off fuel is 15,000 kg, giving a take-off mass of 67,000 kg, below 70,000 kg. Trip fuel is 11,000 kg, so landing mass is 56,000 kg, below 65,000 kg. Dispatch is legal, but no extra payload can be added.
Traps that cost marks
Treating a service bulletin as mandatory; accepting an MEL deferral after its time limit; using dry operating mass as zero-fuel mass; ignoring the CDL; and signing an acceptance without checking that the technical log shows a valid release.
Key points
- Airworthiness is continuing, not a one-off certificate.
- ADs are mandatory; SBs are not unless adopted.
- MEL and CDL deferrals have strict conditions and time limits.
- Defects must be recorded before release or deferral.
- Mass and balance must respect MTOM, MLM and MZFM simultaneously.