ATA Chapters, Maintenance Intervals and Inspections

The ATA 100 chapter system groups every system, structure and engine area under a two-digit code, with sections and groups beneath it, so that ATA 24 is electrical power, ATA 28 fuel, ATA 29 hydraulic power and ATA 71 the reciprocating engine. The same code identifies the system in the manual, in the wiring diagram and in the maintenance record, which is what makes records traceable.

Maintenance intervals are set in hours, in cycles, in calendar time, or in a combination. Inspections layer on top: the daily or pre-flight check, the annual inspection, the 100-hour inspection for aircraft operated for hire, the progressive inspection programme, and the manufacturer’s maintenance programme with its A, C and heavy check intervals. Life-limited parts override all of them and retire on a published limit regardless of condition.

Airworthiness directives are mandatory and carry their own compliance times, which may be expressed as a threshold, a calendar limit or an inspection interval. Track compliance per airframe, engine, propeller or appliance, recording the method of compliance, the date and the signature, and verify status against the authority’s current database rather than a printed copy.

Neither an interval nor an inspection has been performed until the entry is written, dated, referenced to approved data and signed by an authorised person. An expired inspection, an uncomplied directive or a missing life-limited record makes the aircraft unairworthy regardless of how it looks.