---
title: "CS 25.685 Control system details — CS-25 · Avioverse"
description: "(See AMC 25.685) (a) Each detail of each control system must be designed and installed to prevent jamming, chafing, and interference from cargo…"
url: "https://avioverse.aero/regulations/easa/cs-25/subpart-d/cs-25-685"
---

# CS 25.685 Control system details

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

IR Implementing rule

## CS 25.685 Control system details

(See AMC 25.685)

(a) Each detail of each control system must be designed and installed to prevent jamming, chafing, and interference from cargo, passengers, loose objects or the freezing of moisture. (See AMC 25.685(a).)

(b) There must be means in the cockpit to prevent the entry of foreign objects into places where they would jam the system.

(c) There must be means to prevent the slapping of cables or tubes against other parts.

(d) CS 25.689 and CS 25.693 apply to cable systems and joints.

\[Amdt 25/18]

IR · CS 25.685 — CS-25 · ED Decision 2016/010/R · CS-25 Easy Access Rules · EAR revision 26 Jan 2023

AMC Acceptable means of compliance

## AMC 25.685(a) Control system details

In assessing compliance with CS 25.685(a) account should be taken of the jamming of control circuits by the accumulation of water in or on any part which is likely to freeze. Particular attention should be paid to the following:

a. The points where controls emerge from pressurised compartments.

b. Components in parts of the aeroplane which could be contaminated by the water systems of the aeroplane in normal or fault conditions; if necessary such components should be shielded.

c. Components in parts of the aeroplane where rain and/or condensed water vapour can drip or accumulate.

d. Components inside which water vapour can condense and water can accumulate.

AMC · AMC 25.685(a) — CS-25 · ED Decision 2003/2/RM · CS-25 Easy Access Rules · EAR revision 26 Jan 2023

[All rules in SUBPART D – DESIGN AND CONSTRUCTION](https://avioverse.aero/regulations/easa/cs-25/subpart-d)

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.