Part 66 and 147 changes: E propulsion requirements

Closed 28 Mar 2024

Opened 6 Feb 2024

Contact

Airworthiness Policy Team

AWConsultations@caa.co.uk

Feedback updated 5 Sep 2025

We asked

We asked for feedback on a proposal to amend the legislation to introduce the following:

  • ensure the continuing airworthiness of electric and hybrid propulsion aircraft;
  • embrace non-conventional aircraft and aircraft with non-conventional powerplants, where some regulatory gaps have been identified;
  • support, more generally, the development of new technologies;
  • ensure smooth and flexible transitioning of AML holders in the current subcategories to obtain certification privileges for the maintenance of non-conventional aircraft; and
  • support the competitiveness of the UK industry. One objective of the legal framework on which we are consulting is to provide a level playing field while maintaining a high uniform level of civil aviation safety in the UK.

The focus was to close the gap in UK Regulation (EU) No. 1321/2014 in relation to the certification of maintenance of manned aircraft that are not conventional or have a powerplant other than a piston engine or turbine.

The consultation also proposed corrections to Appendix VIII - Basic examination standard for category L aircraft maintenance licence.

This consultation closed in March 2024.

You said

Proposals moved to a new rulemaking task.

The CAA received many comments in response to the consultation on the Part 66 and 147 proposals, in particular for the addition of electronic powerplant to the AML and amendments considering non-conventional aircraft. You highlighted a number of challenges with the proposals.

Appendix VIII – Basic Examination standard for category L aircraft maintenance licence.

There were many comments received regarding Appendix VIII and the potential impact of the new requirements.

We did

We acknowledge the responses and thank all responders for their suggestions.

Proposals moved to a new rulemaking task.

As a result of the consultation responses, proposed amendments for electric propulsion will now be revised and published in a further consultation under the new rulemaking task - RMT 0201. See the CAA Policy and Rulemaking Tracker for more information.

Safety policy and legislation project tracker | UK Civil Aviation Authority

Appendix VIII - Basic Examination Standard for Category L Aircraft Maintenance Licence

The requirements for a stand down period were omitted from the regulation on its initial drafting by EASA. This has since been corrected by EASA and will now be amended by the CAA. However, in response to your comments, the period between resits has been amended to allow for a 12-month rolling period. These amendments will enter the regulation via the Aviation Safety (Amendment) Regulations 2025.

The CAA is undergoing discussions with the BBAC and BGA to support the transition to meeting the new requirements.

 

In Annex 3 (part-66), Appendix 8 (basic examination standard for category L aircraft maintenance licence), at the end of point (a)(v) insert—

[…]

“(vi) subject to point (vii), a failed module may not be retaken for at least 90 days from the date of the failed module examination;

(vii) in cases where an organisation approved in accordance with Annex IV (Part-147), or in accordance with Annex Vd (Part CAO) for balloons or sailplanes only, conducts a course of training tailored to the failed subjects in the particular module, the failed module may then be re-taken after 30 days, provided that where the organisation is approved in accordance with Annex Vd (Part CAO) for balloons or sailplanes it must hold the maintenance and continuing airworthiness management privileges together with an approval from the CAA to conduct the course of tailored training;

(viii) the time periods prescribed by point 66.A.25 apply to each individual module examination, with the exception of those module examinations which were passed as part of another category licence where the licence has already been issued;

(ix) the maximum number of consecutive attempts for each examination is three in a 12-month rolling period”.

 

Overview

The CAA is considering the regulatory requirements, means of compliance and guidance necessary to:

  • ensure the continuing airworthiness of electric and hybrid propulsion aircraft;
  • embrace non-conventional aircraft and aircraft with non-conventional powerplants, where some regulatory gaps have been identified;
  • support, more generally, the development of new technologies;
  • ensure smooth and flexible transitioning of AML holders in the current subcategories to obtain certification privileges for the maintenance of non-conventional aircraft; and 
  • support the competitiveness of the UK industry. One objective of the legal framework on which we are consulting is to provide a level playing field while maintaining a high uniform level of civil aviation safety in the UK.

In order to ensure that we achieve the right level of compliance and guidance we are seeking feedback on the proposals in this consultation. Your feedback will help us to better understand the potential issues or improvements that can be made to our proposals. 

Regulations (also known as Implementing Rules)

Regulations contain requirements which must be complied with. The CAA’s statutory role is to consider the required content of the regulations, consult on our proposed changes to the regulations, take consultation responses into account before forming a final view and then communicating that view to the Secretary of State (Department for Transport) in the form of an Opinion.  Our Opinions are published.  The Secretary of State makes the final decision whether to implement CAA’s proposed changes to the regulations, and the final wording of the regulations.  The proposed wording of the regulations in this consultation may well change if and when the Secretary of State decides to amend the regulations.

AMC and GM

AMC are means by which the requirements in the Implementing Rule and the Essential Requirements of the Basic Regulation to which it relates can be met. However, entities may show compliance by other means. 

An entity may choose to offer an alternative means of compliance (AltMOC) which must be reviewed and accepted by the CAA. However, it is important to note they will lose the presumption of compliance provided by the CAA AMC so it is essential for the operator to demonstrate that the AltMOC meets the intent of the Implementing Rule and the Essential Requirements of the Basic Regulation. 

GM is non-binding and provides explanatory and interpretation material on how to achieve the requirements in the law and the AMC. It contains information, including examples, to assist the applicant with the interpretation of the legislative provisions.

This consultation

This consultation document sets out our proposed changes. It includes text for specific licence sections, GM, AMC and appendices for Part 66 and relevant Part 145 content and the rationale behind each change. 

Why your views matter

It is important to the CAA that everyone has an opportunity to voice their opinion on matters that could affect them. There is also a legal requirement to consult before delivering Opinions in regulations to the Secretary of State and when adopting new or amending AMC and GM, due to the legal status of these documents.  

We welcome comments from every sector of the community. This includes the general public, government agencies and all sectors of the aviation industry, whether as an aviator, aviation consumer and/or provider of related products and services.

How to respond

The response window has been extended until 28 March 2024. We cannot take into account comments received after this date. We will assume that all responses can be published once the consultation has closed. There is an option to request for your name to remain private, but in any event your email address will never be published.

Please submit your comments below. 

What happens next

At the end of the response period, we will review and publish each comment and submission received.

Your feedback will be used to inform our Opinion to the Secretary of State on our proposed changes to the regulations and to refine the AMC and GM and guide the development of the licence and regulatory changes.

Audiences

  • General Aviation
  • Regulatory bodies

Interests

  • Airworthiness
  • AMC & GM consultations
  • Licensing