21.A.433 Requirements for approval of a repair design

Annex I · Regulation (EU) No 748/2012 · EAR revision 27 Nov 2025

IRImplementing rule

21.A.433Requirements for approval of a repair design

(a)A repair design shall only be approved:

1.when it has been demonstrated, following the certification programme referred to in point 21.A.432C(b), that the repair design complies with the type-certification basis and the environmental protection requirements incorporated by reference in, as applicable, either the type certificate, the supplemental type certificate or the APU ETSO authorisation, as well as with any amendments established and notified by the Agency in accordance with point 21.B.450;

2.when compliance with the type-certification basis and the environmental protection requirements that apply in accordance with point (a)1 has been declared and the justifications of compliance have been recorded in the compliance documents;

3.when no feature or characteristic has been identified that may render the product, the UAS or the CMU unsafe for the use for which certification is requested;

4.when the applicant has specified that it has provided certification data on the basis of an arrangement with the owner of the type-certification data in accordance with point 21.A.432C(b)(7):

(i)when the holder has indicated that it has no technical objection to the information submitted under point (a)(2) of this point; and

(ii)when the holder has agreed to collaborate with the repair design approval holder to ensure the discharge of all the obligations with regard to the continued airworthiness of the changed product, changed UAS or changed CMU through compliance with point 21.A.451.

5.when, for a repair to an aeroplane subject to point 26.302 of Annex I to Regulation (EU) 2015/640, it has been demonstrated that the structural integrity of the repair and affected structure is at least equivalent to the level of structural integrity established for the baseline structure by point 26.302 of Annex I to Regulation (EU) 2015/640.

(b)The applicant shall submit to the Agency the declaration referred to in point (a)(2) and, on request by the Agency, all necessary substantiation data.

IR · 21.A.433 — Regulation (EU) No 748/2012 · Regulation (EU) 2025/1065 · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025

AMCAcceptable means of compliance

AMC1 21.A.433(a)(5)Requirements for the approval of repairs to large aeroplanes subject to point 26.302 of Part-26

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For repairs that affect fatigue-critical structures of turbine-powered large aeroplanes certified to carry 30 passengers or more, or with a payload capacity of 3 402 kg (7 500 lbs) or more, damage-tolerance evaluations demonstrate compliance with point 21.A.433(a)(5) when the certification basis used for the repair is:

(a)Amdt 19 to CS 25.571, or subsequent amendments; or

(b)the certification basis of the aeroplane, unless it precedes JAR 25.571 Change 7 or 14 CFR §25.571 Amendment 45, in which case the certification basis for the repair should be:

(1)JAR 25.571 Change 7 or 14 CFR §25.571 Amendment 45, or later amendments; or

(2)the specifications used for compliance with the applicable points of Part-s26 for the fatigue-critical structures affected by the repair.

AMC · AMC1 21.A.433(a)(5) — Regulation (EU) No 748/2012 · ED Decision 2021/007/R · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025

AMCAcceptable means of compliance

AMC1 21.A.433(b)Requirements for approval of a repair design

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RECORD KEEPING

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

(1)the identification of the damage and the reporting source;

(2)the major repair design approval sheet identifying the applicable specifications and references of justifications;

(3)the repair drawing and/or instructions and scheme identifier;

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

(5)the structural justification (static strength, fatigue, damage tolerance, flutter, etc.) or references to this 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 airworthiness limitations, the flight manual and the operating manual;

(9)any weight and moment changes; and

(10)special test requirements.

(b)Relevant minor repair documentation includes paragraphs (a)(1) and (a)(3). Other points of paragraph (a) may be included where necessary. If the repair is outside the approved data, a justification for the classification is required.

(c)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.).

(d)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).

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

AMC · AMC1 21.A.433(b) — Regulation (EU) No 748/2012 · ED Decision 2023/014/R · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025

All rules in SECTION A — TECHNICAL REQUIREMENTS

Consolidated from the EASA Easy Access Rules (revision 27 Nov 2025, extracted 17 Aug 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.

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