---
title: "CS 25.973 Fuel tank filler connection — CS-25 · Avioverse"
description: "Each fuel tank filler connection must prevent the entrance of fuel into any part of the aeroplane other than the tank itself."
url: "https://avioverse.aero/regulations/easa/cs-25/subpart-e/cs-25-973"
---

# CS 25.973 Fuel tank filler connection

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

IR Implementing rule

## CS 25.973 Fuel tank filler connection

Each fuel tank filler connection must prevent the entrance of fuel into any part of the aeroplane other than the tank itself. In addition –

(a) Reserved

(b) Each recessed filler connection that can retain any appreciable quantity of fuel must have a drain that discharges clear of each part of the aeroplane;

(c) Each filler cap must provide a fuel-tight seal; and

(d) Each fuel filling point must have a provision for electrically bonding the aeroplane to ground fuelling equipment.

IR · CS 25.973 — 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.