Since the UK’s withdrawal from the European Union, a critical area of divergence involves the recognition of EASA Form 1 as a release certificate for aircraft components.

UK-EU Trade and Cooperation Agreement – A Foundational Framework

The UK-EU Trade and Cooperation Agreement (TCA), effective from January 1, 2021, laid down the principles for mutual recognition of civil aviation products. Under the TCA, the UK CAA recognises:

• EASA Form 1 for the release of new parts, appliances, engines, and propellers from EU-based EASA Part 21 POA (Production Organisation Approval) holders.

• EASA Form 52 is accepted for new, complete aircraft.

This mutual recognition simplifies the export process for EU manufacturers and supports ongoing operations involving UK-registered aircraft. It also ensures a degree of continuity and minimises supply chain disruption, which is crucial for industry stability.

Policy Framework for Recognising EASA Form 1

The UK CAA has issued policy material and guidance that allows EASA Form 1 to be treated as equivalent to UK CAA Form 1, but only in defined scenarios:

• For new components released by an EASA-approved POA.

• For components released before January 1, 2023, which can still be installed on UK-registered aircraft.

• When components originate from states with which the UK has established bilateral working arrangements, and the EASA Form 1 is issued under a mutually accepted process.

Note: This recognition is not open-ended and should always be cross-checked against the most recent guidance and bilateral agreements.

Caveats and Limitations

The UK CAA imposes strict limitations to preserve regulatory control and airworthiness assurance:

• EASA Form 1s issued by UK-based organisations after January 1, 2021, are not valid in the EU, since these organisations no longer fall under EASA oversight. Consequently, such forms are considered “null and void” for EU purposes.

• For Minimal Risk (ML) aircraft, an EASA Form 1 issued by the OEM or its appointed agent was acceptable up to December 31, 2024, but this is conditional. The UK preference is for components to be sourced from a UK approval holder or through recognised bilateral arrangements.

• Where parts are produced using EASA design data but not under the authority of a type certificate holder, such components must carry the “EPA” (European Part Approval) marking and be released using a UK CAA Form 1.

Further Guidance: Use of EASA Design Data for UK-Manufactured Parts – “EPA” Marking and UK CAA Form 1 Release

When a UK-based production organisation manufactures components using EASA design data (e.g. under a Supplemental Type Certificate (STC) or a Part Approval process), but does not hold the original type certificate, these parts are not considered part of the “primary type design.” Therefore, they fall under a supplemental or non-TCH design category.

This scenario triggers the European Part Approval (EPA) mechanism—recognising that the part complies with airworthiness requirements but is separate from the OEM-authorised production chain.

EPA – European Part Approval: Definition and Purpose

EPA stands for European Part Approval and is a specific marking requirement introduced by the UK CAA for identifying parts that:

• Are manufactured using EASA-approved design data, but

• Are not covered by a Type Certificate or by direct authorisation of the TCH.

The EPA mark serves as a clear declaration that the part is approved via a regulatory pathway (such as an EASA-approved STC or ETSO), but not produced under OEM delegation.

UK CAA Requirements for Production and Release

To legally produce and release such parts within the UK aviation system, the following requirements apply:

a) Production Organisation Approval (POA)
The UK-based manufacturer must hold a UK CAA Part 21 POA to produce and certify the part.

b) Design Data Approval
The design data must be:

• Approved by EASA, and

• Legally made available to the manufacturer (e.g., via license, agreement, or ownership of the STC/ETSO).

c) Marking Requirement – EPA
The part must be physically marked with:

• The EPA identifier, and

• A clear part number, serial number (if applicable), and manufacturer details, in accordance with UK CAA Part 21, Subpart Q (Markings of products, parts and appliances).

d) Release Documentation – UK CAA Form 1
The manufacturer must issue a UK CAA Form 1 (not EASA Form 1) as the authorised airworthiness release certificate. The Form 1 must clearly indicate:

• Reference to the EASA design data approval, including reference number (e.g., STC number or ETSO authorization),

• That the part is released under UK production approval, not EU/EASA oversight,

• The appropriate “EPA” classification in Block 12 (Remarks), which distinguishes it from parts produced under type certificate holder authority.

Implications for Operators and Installers

For aircraft operators and CAMOs:

• Verify the airworthiness of the part via both the UK CAA Form 1 and the accompanying EASA design approval reference.

• Ensure compatibility with the aircraft configuration and applicable design limitations.

• Recognise that EPA parts may be subject to installation restrictions—for example, some may only be installed on UK-registered aircraft unless accepted under bilateral agreements.

Limitations and Oversight

Operators and maintenance organisations should note:

• The EPA-marked part cannot be installed on an EU-registered aircraft unless separately accepted by EASA or covered under a mutual recognition agreement.

• The UK CAA remains the competent authority for oversight, surveillance, and quality control of the manufacturing organisation.

Where a UK organisation manufactures components using EASA design data but outside the scope of a TCH, those parts must:

• Be clearly marked with “EPA”,

• Be released using a UK CAA Form 1,

• And be supported by approved EASA design data, such as an STC or ETSO.

This framework allows the continued use of high-integrity European design data while maintaining UK sovereignty over production oversight and certification.

It is essential for manufacturers, operators, and maintenance organisations to align their procedures and documentation practices accordingly to ensure continued compliance and airworthiness traceability.

Strategic and Operational Considerations

While the CAA’s approach facilitates a level of continuity with European manufacturing, it also emphasises UK sovereignty and oversight in aviation regulation. Organisations dealing with cross-border component supply must now be more vigilant in tracking:

• The origin and issuance date of EASA Form 1s.

• The regulatory status of the issuing organisation.

• The applicable working arrangements or bilateral agreements that may support recognition.

Note: For UK operators and CAMOs (Continuing Airworthiness Management Organisations), it is vital to ensure that installation of any component with an EASA Form 1 release complies with CAA policy, especially post-transition deadlines.

Next Steps

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