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Part-ML provides a proportionate framework for continuing airworthiness to correspond to the lower risks associated with 'Light Aircraft' in general aviation.

Part-ML sets out requirements to ensure that 'Light Aircraft' remain airworthy and are in a condition for safe operation. It also establishes the responsibilities of persons and organisations involved in activities related to the continuing airworthiness of these aircraft.

Part-ML

Part-ML simplifies existing maintenance rules and offers a less prescriptive and burdensome approach to maintenance programmes, airworthiness reviews, defects deferments and TBO extensions. It also provides more privileges for pilots, owners, independent certifying staff and small maintenance organisations.

For example:

The Civil Aviation Authority (CAA) will no longer be involved in the approval of maintenance programmes for Light aircraft.

A new Airworthiness Review Certificate (ARC) (CAA Form 15c) has been introduced that can be issued by the CAA, by an approved organisation or by independent Part-66 engineers with an appropriate authorisation.

CAA Generic Requirements listed in Mandatory Requirements for Airworthiness (CAP747), have been revised to ensure their applicability does not contradict Part-ML. For example, GR No. 24 is no longer applicable to Part-21 aircraft, GR No. 11 remains mandatory for both Part 21 and non-Part 21 aircraft.

Definition of light aircraft under Part-ML

Light aircraft means the following non-complex motor-powered aircraft not listed in the air operator certificate of an air carrier licensed in accordance with UK Regulation (EC) No 1008/2008:

  • aeroplanes of 2,730 kg maximum take-off mass (MTOM) or less.
  • rotorcraft of 1,200 kg MTOM or less, certified for a maximum of up to 4 occupants.
  • other ELA2 aircraft (for example sailplanes, balloons, small airships).

Independent Certifying Staff

  • Part-ML introduces an independent certifying staff authorisation which allows licenced engineers to carry out the airworthiness review and issue the Airworthiness Review Certificate in conjunction with the annual inspection for light aircraft within the scope of Part-ML.
  • The authorisation is issued after the applicant has carried out a satisfactory Airworthiness Review under supervision by the Civil Aviation Authority (CAA).
  • The authorisation is limited by Part-ML and the scope of aircraft on the applicant’s licence.
  • Existing ELA 1 authorisations are not valid after 24th March 2020 due to the change in regulations.
  • Applications for an independent certifying staff authorisation should made using Form SRG1015 be submitted to apply@caa.co.uk with 'ML.A.901 Authorisation' in the subject line. 

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