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.