---
title: "CS 25J977 Fuel Tank Outlet — CS-25 · Avioverse"
description: "For essential APUs: There must be a fuel strainer for the fuel tank outlet or for the booster pump."
url: "https://avioverse.aero/regulations/easa/cs-25/subpart-j/cs-25j977-fuel-tank-outlet"
---

# CS 25J977 Fuel Tank Outlet

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

IR Implementing rule

## CS 25J977 Fuel Tank Outlet

For essential APUs:

(a) There must be a fuel strainer for the fuel tank outlet or for the booster pump. This strainer must prevent the passage of any object that could restrict fuel flow or damage any fuel system component.

(b) The clear area of each fuel tank outlet strainer must be at least five times the area of the outlet line.

(c) The diameter of each strainer must be at least that of the fuel tank outlet.

(d) Each finger strainer must be accessible for inspection and cleaning.

\[Amdt 25/1]

IR — CS-25 · ED Decision 2005/006/R · CS-25 Easy Access Rules · EAR revision 26 Jan 2023

[All rules in SUBPART J – AUXILIARY POWER UNIT INSTALLATIONS](https://avioverse.aero/regulations/easa/cs-25/subpart-j)

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.