A Check — A Check — Aircraft Maintenance

A Check

The A Check is the most frequent scheduled maintenance event in the aircraft's maintenance programme. It represents the boundary between daily line checks and deeper base maintenance — more comprehensive than an overnight check but light enough to be completed during an extended ground stop.

Typical A Check Tasks

An A Check typically includes: visual inspection of the aircraft exterior (skin, control surfaces, antennas, landing gear), inspection of accessible interior panels and compartments, check and servicing of fluid levels (hydraulic, oil, water), functional tests of selected systems and avionics, lubrication of specified components, review and clearance of open defects from the technical log, and completion of any tasks from the approved maintenance programme falling due at this interval.

Interval Variability

A Check intervals are not uniform across airlines or aircraft types. The interval depends on the Aircraft Maintenance Programme (AMP) approved by the airline's national aviation authority. Modern aircraft (A350, B787) tend to have longer A Check intervals than older types, reflecting improved reliability and health monitoring.

Flight Hours vs Calendar Time

The trigger for an A Check is whichever comes first: the flight hour threshold or the calendar time limit. A long-haul aircraft accumulating flight hours rapidly may hit the hour threshold before the calendar limit; a short-haul aircraft making many short flights may reach calendar time first.

Location

A Checks are performed at the airline's main base or at approved outstations. The aircraft does not need to enter a hangar — most A Check tasks can be completed on the ramp or in a line maintenance bay.