---
title: "GM No 2 to 21.A.128 Acceptable functional test – Variable pitch propellers — Annex I, Initial Airworthiness · Avioverse"
description: "The functional tests required for a new propeller will be specified by the propeller design organisation and should normally include a number of complete…"
url: "https://avioverse.aero/regulations/easa/initial-airworthiness/annex-i/section-a-technical-requirements/gm-no-2-to-21-a-128-acceptable-functional-test-variable-pitch-propellers"
---

# GM No 2 to 21.A.128 Acceptable functional test – Variable pitch propellers

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

Official sources: [EASA Easy Access Rules (opens in a new tab)](https://www.easa.europa.eu/en/document-library/easy-access-rules/easy-access-rules-initial-airworthiness-and-environmental) · [EUR-Lex 2012/748 (opens in a new tab)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0748)

GM Guidance material

## GM No 2 to 21.A.128 Acceptable functional test – Variable pitch propellers

The functional tests required for a new propeller will be specified by the propeller design organisation and should normally include a number of complete cycles of control throughout the propeller pitch and rotational speed ranges. In addition, for feathering and/or reversing propellers, several cycles of feathering operation and reversing operation from the lowest normal pitch to the maximum reverse pitch, should normally be required.

GM — Regulation (EU) No 748/2012 · ED Decision 2012/020/R · 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 2 Nov 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.