Part-ML vs Part-M: Which Continuing Airworthiness Rules Apply to Your Aircraft?

Part-ML (Annex Vb) applies to other-than-complex motor-powered aircraft that are: aeroplanes of 2,730 kg MTOM or less, helicopters of 1,200 kg MTOM or less certified for up to four occupants, other ELA2 aircraft, and certain non-conventional aircraft. If such an aircraft is listed on the air operator certificate of a licensed air carrier, Part-M (Annex I) applies instead. Every other aircraft within the regulation's scope falls under Part-M (Article 3 of Regulation (EU) No 1321/2014).

This guide is for American owners and operators of aircraft on an EU Member State register, and for U.S. buyers considering one. It uses only the consolidated text of Regulation (EU) No 1321/2014 dated 22 February 2026 and EASA's continuing airworthiness FAQ. The text of Annex I (Part-M) itself is not part of this source set, and neither are FAA rules, so the comparison focuses on scope and on the differences the regulation and FAQ spell out.

Step 1: Is the aircraft covered by the regulation at all?

Article 1(a) covers aircraft registered in a Member State (unless oversight has been delegated to a third country and they are not used by an EU operator), and aircraft registered in a third country and used by an EU operator where oversight has been delegated to a Member State. Two special cases sit beside the Part-M/Part-ML split:

• Aircraft with a permit to fly follow the continuing airworthiness arrangements in that permit (Article 3(4)).
• Third-country aircraft dry leased-in by a licensed air carrier follow Annex Va (Part-T) (Article 3(6)).

That matters for U.S.-registered aircraft based in Europe. EASA's FAQ says the regulation applies to third-country-registered aircraft only if their oversight has been delegated to a Member State (then Part-M or Part-ML applies) or if they are dry leased-in by an EU licensed air carrier (then Part-T). Otherwise, the FAQ points to the Basic Regulation, Regulation (EU) 2018/1139, and its Annex V essential requirements for operators established in the EU, overseen by the authority of the operator's State. What FAA rules require of such an aircraft is outside this base.

Step 2: Is it a complex motor-powered aircraft?

Part-ML is only for other than complex motor-powered aircraft. Article 2(u) defines a complex motor-powered aircraft as:

• an aeroplane with MTOM above 5,700 kg, or certified for more than 19 passenger seats, or for a minimum crew of two pilots, or equipped with turbojet engine(s) or more than one turboprop engine;
• a helicopter certified for MTOM above 3,175 kg, or more than nine passenger seats, or a minimum crew of two pilots;
• a non-conventional aircraft certified for MTOM above 5,700 kg, or above 3,175 kg if it can hover (maintain zero horizontal speed), or more than nine passenger seats.

There is one nuance for twins: Article 3(7) says aeroplanes of 5,700 kg MTOM or less with multiple turboprop engines are to be treated, for a listed set of points in Part-M, Part-145, Part-66, Part-CAMO and Part-CAO, under the requirements for other-than-complex aircraft. They are still above the Part-ML weight ceiling if heavier than 2,730 kg.

Step 3: Apply the Part-ML thresholds

Article 3(2) and point ML.1(a) list four groups. Note that the aeroplane limit (2,730 kg) is higher than the ELA2 aeroplane limit (2,000 kg), so a non-complex aeroplane between the two is in Part-ML without being ELA2.

For reference, Article 2(k) defines ELA1 as including aeroplanes of 1,200 kg MTOM or less that are not complex, sailplanes and powered sailplanes of 1,200 kg or less, and balloons and airships within stated gas or hot-air volumes (for example 3,400 m³ for hot-air balloons). ELA1 matters elsewhere, for instance for the L2 license subcategory in Part-66.

Step 4: The air carrier exception

Even a light aircraft goes back to Part-M once it is listed on the AOC of an air carrier licensed under Regulation (EC) No 1008/2008. Article 3(3) sets the entry conditions for listing: its maintenance program approved by the competent authority under M.A.302, the due maintenance performed and certified under 145.A.48 and 145.A.50, and an airworthiness review carried out with a new ARC issued under M.A.901.

Worked examples

Applying only the thresholds above to hypothetical aircraft, all registered in a Member State and not on a licensed air carrier's AOC:

• Single-piston aeroplane, 1,150 kg MTOM: not complex, under 2,730 kg, also ELA1. Part-ML.
• Single-turboprop aeroplane, 2,600 kg MTOM, one pilot: not complex (one turboprop, under 5,700 kg), under 2,730 kg. Part-ML.
• Same type at 3,200 kg MTOM: still not complex, but over 2,730 kg and not ELA2. Part-M.
• Piston helicopter, 1,100 kg MTOM, certified for five occupants: over the four-occupant limit. Part-M.
• Composite sailplane, 600 kg: ELA2. Part-ML.
• Twin-turboprop aeroplane, 5,000 kg: complex under Article 2(u) (more than one turboprop), with Article 3(7) applying other-than-complex requirements for listed points. Part-M.

Who answers for a Part-ML aircraft

Once an aircraft is in Part-ML, two definitions in point ML.1 decide who deals with whom. The competent authority is the one designated by the Member State of registry (ML.1(b)), wherever the owner lives. The owner is the person responsible for continuing airworthiness: the registered owner, the lessee under a leasing contract, or the operator (ML.1(c)(3)). Where the aircraft is leased and the lessee appears in the registration document or the lease, the owner's responsibilities pass to the lessee (ML.A.201(b)).

For an American owner, that means the airworthiness review certificate copy, any occurrence report and any CAMO/CAO contract notice go to the authority of the Member State where the aircraft is registered. Occurrence reports on conditions endangering flight safety are due as soon as possible and no later than 72 hours after the condition is identified (ML.A.202(d)).

What actually changes for an owner

Without the Part-M text, the comparison is limited to what the base's sources state. Those differences are concrete:

1. Maintenance program: under Part-ML the AMP is declared by the owner or approved by the CAMO/CAO (ML.A.302(b)); EASA's FAQ notes Part-ML AMPs are not subject to approval by the competent authority, while Part-M AMPs can be approved indirectly only under conditions.
2. Minimum inspection program: Part-ML provides a MIP with annual/100-hour intervals and a 1-month or 10-hour tolerance (ML.A.302(d)).
3. Tolerance arithmetic: the FAQ explains that under Part-ML the next interval runs from the accomplishment date when the tolerance is used, whereas for a Part-M one-time extension it is normally calculated from the previous due date.
4. Pilot-owner and independent certifying staff: Part-ML allows limited pilot-owner maintenance (ML.A.803) and, for Part-NCO aircraft, airworthiness reviews by independent certifying staff during the 100-hour/annual inspection (ML.A.901(b)(4)).
5. Organizations: the CAO, a combined organization, can only serve non-complex aircraft outside licensed air carriers (CAO.A.010).

To check a particular aircraft, ask the EASA continuing airworthiness knowledge base a question such as “Which aircraft fall within the scope of Part-ML rather than Part-M?” and give the MTOM, seats and engines. For detailed Part-M requirements, it will tell you that its sources do not cover them.

This article explains the regulation's scope; classification of a specific aircraft depends on its type certificate data and the competent authority. Sources: EUR-Lex and EASA's FAQ. The Part-M annex and EASA's AMC/GM are not in the knowledge base.