A-checks belong to a higher level of scheduled maintenance procedures. Normally it is performed at a designated maintenance station on route and includes the opening of all access panels for checking and servicing certain items. Special tooling, test equipment and servicing is required.
Examples of A-check items include:
- General external visual inspection of aircraft structure for evidence of damage, deformation, corrosion, and missing parts
- Crew oxygen system pressure
- Operation of emergency lights
- Lubricating the nose gear retract actuator
- The pressure of parking brake accumulator
- Testing the Built-in Test Equipment (BITE) and Flap/Slat Electronics Unit.