FAQ n.19104

Shall the maintenance data be available and controlled at all times, even if there is no maintenance work going, or shall it be available only during the performance of maintenance?


Maintenance data has direct influence on many processes of the approved maintenance organisation (AMO) and contributes to demonstrate the overall capability of the organisation to perform maintenance.

The maintenance data either can be arranged directly by the AMO or provided by the customer/operator as specified by 145.A.45(a), M.A.609 or CAO.A.055(a). In both cases, the AMO should demonstrate that the maintenance data used, regardless of the source, is up-to-date. To discharge this responsibility, a procedure should be established to:

(a) control the amendment status of any documents being used;


(b) regularly check that all amendments are being received, e.g. by subscribing to a document amendment scheme (sufficient in case of direct access to the maintenance data through the DAH/OEM. The subscription to the maintenance data distribution system of the customer/operator is insufficient, additional independent verifications through the original author shall be done).

When the maintenance data is arranged directly by the AMO it shall be available and controlled continuously.

There are certain situations when the maintenance data can be obtained only through the customer/operator. One of the examples would be the maintenance data for the large aircraft. The maintenance data coming from the TC holder is usually customised because of the model/configuration/modification/order of aircraft, so it is normally not possible for the AMO to have this customised maintenance data directly from TC holder without having an aircraft of that type under the contract.

When the maintenance data is provided by the customer/operator, it shall be held and controlled by the AMO during maintenance on the concerned aircraft/component. Whenever the maintenance data is not available or not current, the maintenance shall not be performed and released.

Additionally, as part of the obligation for maintenance records, used maintenance data shall be:

  • recorded (in compliance with 145.A.55(c), M.A.614(c) or CAO.A.090(b)) 
  • Remark: Manuals issued by the (S)TC (Supplementary Type Certificate) holder such as  AMM and CMM do not need to be stored as a record. Recording the revision status of such manual may be sufficient [AMC 145.A.55(c), AMC M.A.614(c)]; and
  • accessible for auditing purpose

to demonstrate that the organisation worked in compliance with their respective requirements.

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