---
title: "21.A.251 Terms of approval — Annex I, Initial Airworthiness · Avioverse"
description: "The terms of approval shall identify the types of design work, the categories of products, parts, appliances, UAS, CMUs or CMU components for which the…"
url: "https://avioverse.aero/regulations/easa/initial-airworthiness/annex-i/section-a-technical-requirements/21-a-251"
---

# 21.A.251 Terms of approval

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

IR Implementing rule

## 21.A.251 Terms of approval

The terms of approval shall identify the types of design work, the categories of products, parts, appliances, UAS, CMUs or CMU components for which the design organisation holds a design organisation approval, and the functions and duties that the organisation is approved to perform with regard to the airworthiness, operational suitability data and environmental compatibility characteristics of the products, UAS or CMUs. For design organisation approvals covering type-certification or European Technical Standard Order ([ETSO](https://avioverse.aero/glossary/easa/etso)) authorisation for auxiliary power units (APUs), the terms of approval shall additionally contain the list of products, CMUs or APUs. Those terms shall be issued as part of a design organisation approval.

IR · 21.A.251 — Regulation (EU) No 748/2012 · Regulation (EU) 2025/1065 · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025

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

Consolidated from the EASA Easy Access Rules (revision 27 Nov 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.