Minimum Equipment List (MEL)

What is a Minimum Equipment List (MEL)?

A Minimum Equipment List (MEL) is an operator-specific document, approved by the relevant aviation authority, which details the equipment and systems that may be inoperative for a flight to proceed without compromising safety. The MEL is derived from the Master Minimum Equipment List (MMEL) provided by the aircraft manufacturer and adapted to the operator's specific configuration and operational needs.

MEL in Aviation Law

The MEL is a legal requirement for commercial air transport operations under ICAO Annex 6 and EASA regulations (such as Part-CAT). It ensures compliance with airworthiness standards set out in ICAO Annex 8 and national or regional regulations. The MEL must be carried on board and referenced during preflight checks and when defects are discovered.

MEL Structure and Use

• Lists items that may be inoperative, under what conditions, and for how long
• Specifies any required procedures, performance penalties, or operational limitations
• Is valid only if the aircraft is operated within the specified conditions and time limits
• Does not permit operation with inoperative items that are required by other regulations, the aircraft's Certificate of Airworthiness, or operational rules

MEL vs. MMEL

The MMEL is a generic list for a particular aircraft type, while the MEL is tailored to each operator's specific aircraft and routes. The MEL may be more restrictive but never less so than the MMEL.

ICAO MEL Requirements

ICAO requires that each contracting State ensure operators have an approved MEL for each aircraft type used in commercial operations. The MEL must be kept up to date and reflect the current configuration of the aircraft.