AMC 21.A.433(b) and 21.A.447 Repair design and record keeping    

CAA ORS9 Decision No. 1

1. Relevant substantiation data associated with a new major repair design and record keeping should include:

a. the identification of the damage and the reporting source;

b. the major repaAir design approval sheet identifying the applicable specifications and references of justifications;

c. the repair drawing and/or instructions and scheme identifier;

d. the correspondence with the holder of the type certificate (TC), supplemental type certificate (STC), or auxiliary power unit UK technical standard order (APU UKTSO) authorisation, if its advice on the design has been sought;

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

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

g. the effect on the maintenance programme;

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

i. any weight and moment changes; and

j. special test requirements.

2. Relevant minor repair documentation includes paragraphs 1(a) and (c). Other points of paragraph 1 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, 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 21.A.433(a)(4).

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