AMC1 21.A.5(a) and 21.A.433(b) Repair design and record-keeping

CAA ORS9 Decision No. 40

1. The relevant substantiation data related to a new major repair design and record-keeping should include:

   1. identification of the damage and of the source of the report;

   2. the major repair design approval sheet that identifies the applicable specifications and the references of the justifications;

   3. the repair drawing and/or instructions, and the scheme identifier;

   4. any correspondence with the holder of the type certificate (TC), supplemental type certificate (STC), or auxiliary power unit (APU) United Kingdom technical standard order (UKTSO) authorisation, if their advice on the design was sought;

   5. the structural justification (static strength, fatigue, damage tolerance, flutter, etc.) or references to that data;

   6. the effect on the aircraft, engines and/or systems (performance, flight handling, etc., as appropriate);

   7. the effect on the maintenance programme;

   8. the effect on the airworthiness limitations, the flight manual, and the operating manual;

   9. any change in the weight and moment; and

   10. any special test requirements.

2. The relevant minor repair documentation includes points (a)(1) and (a)(3). Other elements of point (a) may be included, where necessary. If the repair is outside the approved data, a justification for the classification is required.

3. Special consideration should be given to repairs that impose subsequent limitations on the part, product or appliance (e.g. engine turbine segments that may only be repaired a finite number of times, the number of repaired turbine blades per set, the oversizing of fastener holes, etc.).

4. Special consideration should also be given to life-limited parts and critical parts, notably with the involvement of the TC or STC holder, when deemed necessary under point 21.A.433(a)(4).

5. Repairs to engines or to APU critical parts would normally be accepted only with the involvement of the TC holder.