Part-ML or Part-M? Working Out Which EASA Rules Cover Your Aircraft

Under Article 3 of Regulation (EU) No 1321/2014, Part-ML governs other-than-complex motor-powered aircraft within four groups: aeroplanes up to 2,730 kg MTOM, helicopters up to 1,200 kg MTOM certified for no more than four occupants, other ELA2 aircraft, and certain non-conventional aircraft. Part-M governs everything else in scope, including any of those light aircraft once listed on the air operator certificate of a licensed air carrier.

Before you start: register and regime

These rules attach to the aircraft's register, not the owner's address. Article 1 applies them to aircraft registered in a Member State, unless oversight has been delegated to a third country and the aircraft is not used by an EU operator, and to third-country-registered aircraft used by an EU operator whose oversight has been delegated to a Member State.

For readers in the UK: since Brexit the United Kingdom applies its own CAA continuing airworthiness rules, and those are not covered by the sources behind this article. Nothing here describes the UK equivalent of Part-ML. What follows is drawn from the EU regulation as consolidated on 22 February 2026 and from EASA's continuing airworthiness FAQ; Annex I (Part-M) itself is not among those sources.

The definitions you need

Complex motor-powered aircraft (Article 2(u))

• Aeroplanes: MTOM over 5,700 kg, more than 19 passenger seats, a minimum crew of two pilots, or turbojet engine(s) or more than one turboprop.
• Helicopters: MTOM over 3,175 kg, more than nine passenger seats, or a minimum crew of two pilots.
• Non-conventional aircraft: MTOM over 5,700 kg, over 3,175 kg if able to hover, or more than nine passenger seats.

ELA1 and ELA2 (Article 2(k) and (ka))

The Part-ML test, step by step

1. Is the aircraft within Article 1 (Member State register, or delegated oversight)? If it holds a permit to fly, its continuing airworthiness follows the arrangements in the permit instead (Article 3(4)).
2. Is it a complex motor-powered aircraft? If yes, Part-M.
3. Does it fit one of the four Part-ML groups: aeroplane up to 2,730 kg; helicopter up to 1,200 kg and certified for up to four occupants; other ELA2 aircraft; non-conventional aircraft up to 1,200 kg if it can hover, or 2,730 kg otherwise? If not, Part-M.
4. Is it listed on the AOC of an air carrier licensed under Regulation (EC) No 1008/2008? If yes, Part-M; if not, Part-ML.

Note the gap between categories: a non-complex aeroplane of 2,400 kg is too heavy to be ELA2 (2,000 kg) but still inside the 2,730 kg Part-ML ceiling. And Article 3(7) adds that aeroplanes of 5,700 kg or less with multiple turboprops, though complex by definition, follow the other-than-complex version of a listed set of Part-M, Part-145, Part-66, Part-CAMO and Part-CAO points.

Examples, from balloons to light twins

Hypothetical aircraft, all on a Member State register and classified purely on the thresholds above: Real classifications depend on the certified MTOM, seating and crew in each type's certification data, so treat the rows as illustrations of the rule rather than rulings.

The flight-school row illustrates a frequent confusion. Commercial use does not by itself move an aircraft to Part-M; only listing on a licensed air carrier's AOC does. But under ML.A.201(e), aircraft of commercial ATOs and DTOs must have their continuing airworthiness managed by a CAMO or CAO, and all maintenance done by approved maintenance organisations.

Moving onto an airline's AOC

Article 3(3) sets three conditions before a Part-ML aircraft can be listed on a licensed air carrier's AOC: its maintenance programme approved by the competent authority under M.A.302; the maintenance due under that programme performed and certified under 145.A.48 and 145.A.50; and an airworthiness review performed with a new ARC issued under M.A.901. In effect, the aircraft has to be brought into the Part-M and Part-145 system before the switch.

Who is responsible once you are in Part-ML

Part-ML places responsibility squarely on the owner, defined in ML.1(c)(3) as the registered owner, the lessee under a leasing contract, or the operator. Under ML.A.201(a), the owner must ensure no flight takes place unless the aircraft is airworthy, any operational and emergency equipment is serviceable or clearly identified as unserviceable, the airworthiness certificate is valid, and maintenance follows the aircraft maintenance programme. A lessee named in the registration document or lease takes on those duties (ML.A.201(b)).

The pilot-in-command is responsible for the pre-flight inspection, which need not be done by an approved organisation or certifying staff (ML.A.201(d)). The competent authority is the one designated by the Member State of registry (ML.1(b)), so an owner living in the UK deals with the authority of the EU country where the aircraft is registered.

Practical differences the sources confirm

• Programme approval: Part-ML AMPs are declared by the owner or approved by a CAMO/CAO, and EASA's FAQ notes they are not subject to approval by the competent authority.
• Inspection tolerance: under Part-ML the next interval runs from when the inspection was done (ML.A.302(d)); the FAQ contrasts this with Part-M one-time extensions, normally counted from the previous due date.
• Who may maintain and review: Part-ML provides for limited pilot-owner maintenance (ML.A.803) and lets independent certifying staff perform airworthiness reviews on Part-NCO aircraft during the 100-hour/annual inspection (ML.A.901(b)(4)).
• Choice of organisation: a CAO is available only for non-complex aircraft not listed on a licensed air carrier's AOC (CAO.A.010).
• Old programmes: AMPs compliant with M.A.302 before 24 March 2020 are deemed compliant with M.A.302 or ML.A.302, as applicable (Article 3(5)).

For a specific aircraft, give the EASA continuing airworthiness knowledge base its MTOM, seats, engines and type of operation, and ask “Which aircraft fall within the scope of Part-ML rather than Part-M?” Questions on detailed Part-M requirements will be flagged as outside the base.

This article explains the EU scope rules; it does not classify any particular aircraft, which depends on its type certificate data. Sources: EUR-Lex and EASA's FAQ. Annex I (Part-M), EASA's AMC/GM and the UK CAA regime are not in the knowledge base.