---
title: "CS 25.1167 Accessory gearboxes — CS-25 · Avioverse"
description: "For aeroplanes equipped with an accessory gearbox that is not certificated as part of an engine – (a) The engine with gearbox and connecting…"
url: "https://avioverse.aero/regulations/easa/cs-25/subpart-e/cs-25-1167"
---

# CS 25.1167 Accessory gearboxes

Large Aeroplanes (CS-25) · CS-25 · EAR revision 26 Jan 2023

IR Implementing rule

## CS 25.1167 Accessory gearboxes

For aeroplanes equipped with an accessory gearbox that is not certificated as part of an engine –

(a) The engine with gearbox and connecting transmissions and shafts attached must be subjected to the test specified in CS-E 160 and CS-E 740, as applicable.

(b) The accessory gearbox must meet the requirements of CS-E 80 and CS-E 590, as applicable; and

(c) Possible misalignments and torsional loadings of the gearbox, transmission, and shaft system, expected to result under normal operating conditions must be evaluated.

IR · CS 25.1167 — CS-25 · ED Decision 2003/2/RM · CS-25 Easy Access Rules · EAR revision 26 Jan 2023

[All rules in SUBPART E – POWERPLANT](https://avioverse.aero/regulations/easa/cs-25/subpart-e)

Consolidated from the EASA Easy Access Rules (revision 26 Jan 2023, 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.