CAAP 42B-1(1)
CASA Maintenance Schedule
6. Periodic Inspection Schedule
6.1 The replacement or overhaul of time-lifed components required in an Airworthiness Limitations Section of the aeroplane’s maintenance manual and any special techniques required by the manufacturer or an Airworthiness Directive are required to be complied with. If it is clear from the terms of the manufacturer’s requirement that the manufacturer considers compliance is optional, then that requirement is optional