Working on EASA-registered Aircraft in the UK After Brexit: Who Can Certify the Work?

Brexit created two separate aircraft maintenance licensing systems. A licence issued by the UK Civil Aviation Authority (CAA) is a UK Part-66 aircraft maintenance licence, while a licence issued by an EASA Member State is an EASA Part-66 licence.

That distinction matters when maintenance is performed in the UK on an aircraft registered in an EASA Member State. Before work can be certified and released to service, the engineer's licence, the maintenance organisation's approval and the aircraft's registration must be compatible.

This guide explains the main certification routes and the checks engineers and maintenance organisations should complete before signing a release to service.

The short answer

In the UK, work on an EASA-registered aircraft may generally be certified by:

• An engineer holding an EASA Part-66 licence issued by an EASA Member State, when properly authorised by the relevant EASA-approved organisation.
• An engineer holding a UK CAA Part-66 licence, where the applicable EASA regulatory framework, maintenance approval or operator arrangement accepts that licence.
• Certifying staff working under an EASA Part-145 or Part-CAO approval, within the scope of their licence, aircraft type privileges, competence and organisation authorisation.
• In limited circumstances, appropriately qualified independent certifying staff acting under the applicable maintenance rules.

Holding a licence alone is not enough. Certification privileges depend on the combination of:

• The aircraft's State of Registry.
• The approval under which the work is performed.
• The engineer's licensing authority.
• The engineer's category and aircraft type privileges.
• The organisation's written authorisation.
• Current competence and maintenance experience.

For the current UK requirements, always check the UK CAA aircraft maintenance engineering guidance and the latest applicable EASA rules before relying on a particular certification route.

Which licence is relevant?

EASA Part-66 aircraft maintenance licence

An EASA Part-66 licence is issued by the competent authority of an EASA Member State. It may be issued as an EASA Form 26 aircraft maintenance licence and can provide the basis for certifying maintenance on aircraft registered in an EASA Member State.

An EASA licence does not automatically give an engineer unrestricted authority to certify every EASA-registered aircraft in every UK workplace. The engineer must hold the relevant category, subcategory and aircraft type privileges, and must be authorised by the approved maintenance organisation.

For example, an engineer may hold an EASA B1 licence but still be unable to certify a particular aircraft type if that type is not included in the licence or if the organisation has not issued the necessary authorisation. EASA's Easy Access Rules for Continuing Airworthiness provide the regulatory context for licensing, maintenance organisations and continuing airworthiness arrangements.

UK CAA Part-66 aircraft maintenance licence

A UK Part-66 licence is issued by the UK CAA and is primarily used within the UK regulatory system. It is not automatically equivalent to an EASA Part-66 licence for work on EASA-registered aircraft.

A UK licence holder may work on an EASA-registered aircraft in the UK, but whether they can certify the work depends on the approval under which the work is being carried out and whether the applicable EASA requirements recognise the individual's licence and authorisation.

This is particularly important where:

• The aircraft is maintained under an EASA Part-145 approval.
• The maintenance organisation is located in the UK but holds approval from an EASA Member State.
• The aircraft operator requires EASA-approved maintenance.
• The work is performed under a contract involving an EASA operator.
• The aircraft will be released to service using an EASA-approved maintenance release system.

A UK Part-66 licence should therefore not be treated as an automatic substitute for an EASA Form 26 licence.

The approval under which the work is performed

EASA Part-145 approval

An EASA Part-145 organisation may employ or contract certifying staff in the UK. It must ensure that each person is appropriately licensed, competent, trained and authorised for the work being certified.

The organisation's exposition and authorisation procedures will normally identify:

• Which licensing authorities are accepted.
• Which aircraft types and tasks the engineer may certify.
• Whether the engineer is acting as certifying staff or support staff.
• Any limitations placed on the authorisation.
• The competence and recency checks required.

A UK-based facility can therefore support EASA-registered aircraft, but its staff cannot certify work simply because the aircraft carries an EASA registration. The release must be made within the privileges permitted by the relevant approval and regulatory framework. The EASA continuing airworthiness organisations guidance is a useful reference when reviewing the organisation's approval basis.

UK CAA Part-145 or Part-CAO approval

A UK CAA-approved organisation may maintain EASA-registered aircraft, subject to the conditions of its approval and the requirements applicable to the aircraft and operator.

The organisation must establish whether its certifying staff can issue the required release to service for that aircraft. In some cases, it may need to use EASA-licensed personnel or rely on specific regulatory provisions, contractual arrangements or acceptance procedures.

The organisation remains responsible for ensuring that certification privileges are valid. An engineer should not determine this solely from the registration marks or from holding a Part-66 licence.

Brexit transition rules for EASA licences

The UK CAA introduced transitional measures after Brexit. These measures were time-limited and should not be confused with continuing mutual recognition between the UK and EASA. Historical exemptions must be checked against current CAA publications rather than assumed to remain valid.

EASA licences issued before the end of the transition period

Under the relevant transitional arrangements, an EASA licence issued and dated before 31 December 2020 could be used to release G-registered aircraft in the UK for up to two years after 31 December 2020:

• When the engineer was authorised by a UK CAA-approved maintenance organisation.
• When the engineer was working as independent certifying staff.

The same licence could also support the release to service of a G-registered aircraft under an EU or EASA approval using Practice 3, as defined in CAA Decision 3, where the maintenance approval had its principal place of business outside the UK.

That transitional period ended. A pre-2021 EASA licence should not now be treated as a permanent UK certification entitlement. Engineers should verify historical provisions using the CAA maintenance organisation and approval guidance.

EASA licences issued during 2021

The UK CAA also provided a specific exemption for EU licences issued by an EU Member State between 1 January 2021 and 31 December 2021. Those licences could be used to certify G-registered aircraft where the maintenance approval had its principal place of business outside the UK.

The exemption was published as ORS4 No. 1468. At the time, the CAA stated that a copy should be printed and retained with the licence holder's records at each maintenance organisation where the holder had been authorised as certifying staff or support staff on the basis of the EASA Form 26 licence.

This was a defined exemption, not a general post-Brexit recognition arrangement. Its applicability and expiry conditions must be checked against the current CAA publication before reliance is placed on it.

EASA licences issued after 1 January 2021

An EASA licence issued and dated after 1 January 2021 was not, by default, eligible to certify G-registered aircraft in the UK under a UK maintenance approval or as independent certifying staff.

The CAA did provide short-term exemptions for certain licence holders who were applying for a UK licence. Those exemptions were intended to manage the post-Brexit licensing transition, not to create an ongoing right for EASA licence holders to certify UK-registered aircraft.

Historical exemptions must be checked by date, aircraft registration, maintenance approval and principal place of business. They cannot be applied broadly to current EASA-registered aircraft work.

EASA-registered aircraft versus G-registered aircraft

The aircraft registration is central.

A G-registered aircraft is a UK-registered aircraft, even if it is operated by a European airline or maintained at an EASA-approved facility. Transitional UK exemptions often referred specifically to the certification of G-registered aircraft.

An aircraft registered in an EASA Member State is different. For that aircraft, the certifying route will normally be determined by:

• The State of Registry.
• The EASA approval under which the work is performed.
• The operator's approved maintenance arrangements.
• The licence and authorisation held by the certifying engineer.

A UK engineer working on an aircraft registered in France, Germany, Ireland or another EASA Member State must establish which authority controls the release to service. The aircraft's physical location in the UK does not, by itself, make UK licensing rules decisive.

Certifying staff and support staff

EASA Part-145 distinguishes between certifying staff and support staff.

Certifying staff may issue the maintenance release within the scope of their authorisation. Support staff assist with maintenance, inspection and technical evaluation but do not necessarily sign the final certificate of release to service.

An engineer may therefore be permitted to perform or inspect work without being permitted to certify it. The organisation's authorisation must clearly define the individual's privileges.

For complex maintenance, an organisation may use support staff with appropriate licence categories and experience, while the final release is signed by authorised certifying staff with the required type and task privileges. This distinction is particularly important when an independent inspection is required. For more detail, see who can perform an independent inspection under UK and EASA Part-145 rules.

Independent certifying staff

Independent certifying staff may be used in circumstances permitted by the applicable maintenance rules. Under the UK system, this can involve the provisions of M.A.801(b)1, particularly for certain aircraft and maintenance situations outside a Part-145 organisation.

This route is not a general alternative to organisational authorisation. The individual must still meet the applicable licensing, competence, experience and documentation requirements, and the aircraft owner or operator must be satisfied that the release is legally valid.

Where an EASA-registered aircraft is involved, the certifier must also consider the requirements of the aircraft's State of Registry and the maintenance programme or approval under which the work is being performed. Independent inspection responsibilities should also be separated from the original task where the applicable rules require independence.

Recency and certification privileges

The validity of a Part-66 licence and the validity of its certification privileges are separate matters.

The licence itself is not necessarily invalidated merely because the holder has not recently worked in maintenance. However, the privileges under 66.A.20(a) are affected by maintenance experience and recency requirements. The organisation must also be satisfied that the individual remains competent for the work being authorised.

In practice, the approved Part-145 or Part-CAO organisation must determine whether the engineer remains competent and current before granting or maintaining an authorisation. An engineer with a valid licence may therefore still be refused certification privileges if the organisation cannot demonstrate adequate recent experience or competence.

Recording experience in a CAP 741 logbook

A CAP 741 logbook can provide useful evidence of maintenance experience, tasks performed, aircraft types and recency. It may support an application for a UK Part-66 licence or help an organisation assess an engineer's competence. For guidance on completing entries, read how to fill out a CAP 741 logbook and review the common CAP 741 mistakes that delay licence applications.

It does not confer certification privileges. A logbook cannot replace:

• The required Part-66 licence.
• Aircraft type privileges.
• An organisation authorisation.
• A competence assessment.
• Compliance with the applicable State of Registry requirements.

The logbook is evidence. The licence and authorisation provide the legal basis for certification.

Ready to check your maintenance evidence? Analyse your Part 66 logbook today and identify gaps in your experience records before a licence or authorisation review.

Recognition of military maintenance experience

Former military engineers may be able to use UK Ministry of Defence experience when applying for, or adding privileges to, a UK Part-66 licence. Recognition normally depends on the nature of the military maintenance, the aircraft and systems involved, the level of responsibility and the evidence supplied through the relevant UK Ministry of Defence pathways.

Military experience can support the competence and experience requirements for a UK licence, but it does not automatically create EASA certification privileges. A former military engineer seeking to certify EASA-registered aircraft still needs the appropriate licensing route and acceptance by the organisation operating under the relevant EASA approval.

What about an FAA A&P certificate?

An FAA Airframe and Powerplant certificate is a US qualification. It is not a UK Part-66 or EASA Part-66 licence and should not be assumed to authorise certification on UK- or EASA-registered aircraft.

An FAA A&P may be relevant where work is performed under an FAA approval or for an aircraft subject to US requirements. For UK and EASA aircraft, however, the engineer must follow the applicable UK CAA, EASA and State of Registry rules. The FAA aircraft mechanic guidance explains the US certification framework, but it does not replace UK or EASA approval requirements.

Practical checks before signing a release to service

Before certifying maintenance on an EASA-registered aircraft in the UK, an engineer should confirm:

• Aircraft registration: Which State of Registry controls the aircraft?
• Maintenance approval: Is the work being performed under UK CAA Part-145, EASA Part-145, Part-CAO or another approval?
• Licence authority: Is the licence issued by the UK CAA or an EASA Member State?
• Licence privileges: Does it include the relevant category, subcategory and aircraft type?
• Organisation authorisation: Has the approved organisation issued written certification authorisation?
• Recency and competence: Can the organisation demonstrate current experience and competence?
• Release format: Which certificate of release to service is required?
• Special arrangements: Does a current exemption, bilateral arrangement or State of Registry procedure apply?

Maintenance records and release documents should be completed in accordance with the applicable approval and technical data. For related guidance, see our article on EASA Form 1 after Brexit.

If any point is unclear, the correct escalation route is the organisation's quality or compliance department, not an assumption based on the engineer's job title or the aircraft's location.

Conclusion

After Brexit, there is no simple rule that a UK engineer can certify any EASA-registered aircraft maintained in the UK. Certification depends on the interaction between the aircraft's registration, the maintenance approval, the engineer's Part-66 licence and the organisation's authorisation.

An EASA Form 26 licence remains the normal licensing foundation for certification under EASA arrangements, while a UK Part-66 licence operates primarily within the UK system. Historical CAA exemptions, including ORS4 No. 1468 and the pre-2021 transitional provisions, were limited measures and should not be treated as continuing mutual recognition.

Engineers should maintain a clear CAP 741 experience record, understand the limits of their licence and obtain written confirmation from the approved maintenance organisation before signing any release to service. Regulations and exemptions can change, so confirm the position with the relevant competent authority and organisation before carrying out certifying work.