145.A.45 Maintenance data

The provisions of GM1 M.A.401(b)(3) and (b)(4), GM1 M.A.401(b)(4) and GM1 ML.A.401(b) apply.

1.The referenced procedure should ensure that when maintenance personnel discover inaccurate, incomplete or ambiguous information in the maintenance data, they should record the details as part of the internal safety reporting scheme specified in point 145.A.202. The procedure should then ensure that the Part-145 approved maintenance organisation notifies the problem to the author of the maintenance data in a timely manner. A record of such communications to the author of the maintenance data should be retained by the Part-145 approved organisation until such time as the author of the maintenance data has clarified the issue by e.g. amending the maintenance data.

2.The referenced procedure should be specified in the MOE.

The referenced procedure should address the need for a practical demonstration by the maintenance personnel proposing the change to the compliance monitoring personnel, of the modified maintenance instruction. Depending on the nature of the maintenance instruction modification, a risk assessment may be required to demonstrate that an equivalent or improved maintenance standard is reached. When satisfied, the compliance monitoring personnel should approve the modified maintenance instruction, and ensure that the author of the maintenance instruction is informed of the modified maintenance instruction. The procedure should include a paper/electronic traceability of the complete process from start to finish, and ensure that the relevant maintenance instruction clearly identifies the modification. Modified maintenance instructions should only be used in the following circumstances:

(a)Where the original intent of the maintenance instruction can be carried out in a more practical or more efficient manner.

(b)Where the original intent of the maintenance instruction cannot be achieved when following the maintenance instructions. For example, where a component cannot be replaced following the original maintenance instructions.

(c)For the use of alternative tools / equipment. Important Note: Critical Design Configuration Control Limitations (CDCCL) are airworthiness limitations. Any modification of the maintenance instructions linked to CDCCL constitutes a change to a (restricted) type certificate that should be approved in accordance with Part 21 or Part 21 Light.

1.‘The relevant parts of the organisation’ means, as appropriate, aircraft base maintenance, aircraft line maintenance, specialised services, component workshops such as engine workshops, mechanical workshops or avionics workshops. Therefore, a common system should be used, for example, throughout the engine workshops, which may be different from that in the aircraft base maintenance.

2.The work cards should differentiate and specify, when relevant, disassembly, accomplishment of tasks, reassembly and testing as well as the error-capturing method (e.g. independent inspection). In the case of a lengthy maintenance task involving a succession of personnel to complete such a task, it may be necessary to use supplementary work cards or worksheets to indicate what was actually accomplished by each individual person.

3.With reference to point 145.A.65(a), human factors should be taken into account during the development of work cards and worksheets.

4.‘Complex or long maintenance tasks’ refers to tasks involving multiple disciplines or multiple shifts, or multiple zones/access opening, special tools, etc., or a combination of these. The stages into which the work cards are to be subdivided should refer to where work can be interrupted. Subdivision should also indicate when a different discipline continues to work if no separate work cards are provided.

5.Where required by the operator/CAMO/CAO to use their work card or worksheet system, the maintenance organisation should assess the system for compliance with the maintenance organisation procedures, for example, the subdivision of complex or long maintenance tasks.

1.Data being made available to personnel maintaining aircraft means that the data should be available in close proximity to the aircraft being maintained for supervisors, mechanics and certifying staff to study.

2.Where computer systems are used, the number of computer terminals should be sufficient in relation to the size of the work programme to enable easy access, unless the computer system can produce paper copies. Where microfilm or microfiche readers/printers are used, a similar requirement is applicable.

To keep data up-to-date, a procedure should be set up to monitor the amendment status of all data and maintain a check that all amendments are being received by being a subscriber to any document amendment scheme. Special attention should be given to mandatory instructions and associated airworthiness limitations published by design approval holders or the declarant of a declaration of design compliance.