---
title: "CS 25.1505 Maximum operating limit speed — CS-25 · Avioverse"
description: "The maximum operating limit speed (VMO/MMO, airspeed or Mach number, whichever is critical at a particular altitude) is a speed that may not be…"
url: "https://avioverse.aero/regulations/easa/cs-25/subpart-g/cs-25-1505"
---

# CS 25.1505 Maximum operating limit speed

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

IR Implementing rule

## CS 25.1505 Maximum operating limit speed

The maximum operating limit speed (VMO/MMO, airspeed or Mach number, whichever is critical at a particular altitude) is a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent), unless a higher speed is authorised for flight test or pilot training operations. VMO/MMO must be established so that it is not greater than the design cruising speed VC and so that it is sufficiently below VD/MD or VDF/MDF, to make it highly improbable that the latter speeds will be inadvertently exceeded in operations. The speed margin between VMO/MMO and VD/MD or VDF/MDF may not be less than that determined under CS 25.335(b) or found necessary during the flight tests conducted under CS 25.253.

IR · CS 25.1505 — CS-25 · ED Decision 2003/2/RM · CS-25 Easy Access Rules · EAR revision 26 Jan 2023

[All rules in SUBPART G – OPERATING LIMITATIONS AND INFORMATION](https://avioverse.aero/regulations/easa/cs-25/subpart-g)

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.