---
title: "M.A.304 Data for modifications and repairs — Part-M · Avioverse"
description: "A person or organisation repairing an aircraft or a component, shall assess any damage."
url: "https://avioverse.aero/regulations/easa/continuing-airworthiness/part-m/section-a-technical-requirements/m-a-304"
---

# M.A.304 Data for modifications and repairs

Annex I (Part-M) · Regulation (EU) No 1321/2014 · EAR revision 2 Sep 2025

IR Implementing rule

## M.A.304 Data for modifications and repairs

A person or [organisation](https://avioverse.aero/glossary/easa/organisation) repairing an [aircraft](https://avioverse.aero/glossary/easa/aircraft) or a [component](https://avioverse.aero/glossary/easa/component), shall assess any damage. Modifications and repairs shall be carried out using, as appropriate, the following data:

(a) approved by the Agency;

(b) approved by a design organisation complying with Annex I (Part 21) to Regulation (EU) No 748/2012;

(c) contained in the requirements referred to in point 21.A.90B or 21.A.431B of Annex I (Part 21) to Regulation (EU) No 748/2012;

(d) contained in the requirements referred to in point 21L.A.62, 21L.A.102, 21L.A.202 or 21L.A.222 of Annex Ib (Part 21 Light) to Regulation (EU) No 748/2012;

(e) declared by a declarant of a declaration of design compliance complying with Annex Ib (Part 21 Light) to Regulation (EU) No 748/2012.

IR · M.A.304 — Regulation (EU) No 1321/2014 · Regulation (EU) 2022/1360 · Continuing Airworthiness Easy Access Rules · EAR revision 2 Sep 2025

AMC Acceptable means of compliance

## AMC M.A.304 Data for modifications and repairs

A person or [organisation](https://avioverse.aero/glossary/easa/organisation) repairing an [aircraft](https://avioverse.aero/glossary/easa/aircraft) or [component](https://avioverse.aero/glossary/easa/component) should assess the damage against published approved or declared repair data and the action to be taken if the damage is beyond the limits or outside the scope of such data. This could involve any one or more of the following options: repair by replacement of damaged parts, requesting technical support from the type certificate holder, the declarant of a declaration of design compliance or from an organisation approved in accordance with Part 21 and finally Agency approval of the particular repair data.

AMC · AMC M.A.304 — Regulation (EU) No 1321/2014 · ED Decision 2023/013/R · Continuing Airworthiness Easy Access Rules · EAR revision 2 Sep 2025

[All rules in SECTION A — TECHNICAL REQUIREMENTS](https://avioverse.aero/regulations/easa/continuing-airworthiness/part-m/section-a-technical-requirements)

Consolidated from the EASA Easy Access Rules (revision 2 Sep 2025, extracted 13 Oct 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.