CAR-M - Continuing Airworthiness
The continuing airworthiness chain
CAR-M sets out how an aircraft is kept airworthy throughout its life. The central actor is the Continuing Airworthiness Management Organisation (CAMO), which manages the aircraft's airworthiness, or the operator/owner where no CAMO is required. The CAMO produces and controls the maintenance programme, tracks airworthiness directives (ADs) and service bulletins, manages modifications and repairs, and controls mass and balance and components with life limits.
The key document is the aircraft maintenance programme (AMP), approved by DGCA (or accepted under defined criteria), which schedules tasks and intervals. The Certificate of Release to Service (CRS) returns the aircraft to service after maintenance; the Airworthiness Review Certificate (ARC) is a separate periodic confirmation of continuing airworthiness, valid for a limited period (commonly one year) and renewed after an airworthiness review.
Traps
Questions love to confuse the CRS (after maintenance) with the ARC (periodic airworthiness confirmation). Another trap is thinking the AMO manages continuing airworthiness - that is the CAMO's job, even if the same company holds both approvals. Also remember ADs are mandatory; service bulletins are generally not unless made mandatory by the authority or the AMP.
Worked example
An aircraft completes a C-check; the AMO issues the CRS. That does not renew the ARC. The CAMO must still complete the airworthiness review and issue/renew the ARC before the aircraft can continue to be operated.
Rule of thumb: CAMO = manages airworthiness; AMO = performs and certifies maintenance; ARC = periodic proof; CRS = after-work release.