Airworthiness Lifecycle: Design to Service
The EASA path from a type certificate and its data sheet to the certificate of airworthiness for one aircraft.
Dionysis KefalasUpdated 6 min readFor Part-21 and CAMO staff
Part 1 of 6 in EASA Part-21 Initial Airworthiness Show parts
Quotes checked on against EASA Easy Access Rules for Initial Airworthiness and Environmental Protection (Regulation (EU) No 748/2012, Part-21) — 27 Nov 2025 revision.
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From a blank sheet to a flying aircraft
The certificate of airworthiness on one aircraft sits at the end of a longer trail: a type certificate for the design, the data that certificate carries, and then the certificate for that airframe. This guide walks that arc under Regulation (EU) No 748/2012, and points onward to the continuing-airworthiness guides.
Design and demonstrating compliance
A new aircraft, engine or propeller starts as a design measured against a type-certification basis. That basis is drawn from certification specifications, which are the subject of the next guide. How an applicant shows capability and compliance, and how the Agency issues the type certificate, is covered in Type Certification.
The type certificate, and everything that comes with it
When the design is approved, the type certificate is a package. This point lists what it includes.
The type-certificate and restricted type-certificate shall include the type design, the operating limitations, the instructions for continued airworthiness, the type-certificate data sheet for airworthiness and emissions, the applicable type-certification basis and environmental protection requirements with which the Agency records compliance, and any other conditions or limitations prescribed for the product, the UAS orthe CMU in the applicable certification specifications and environmental protection requirements. The aircraft type-certificate and restricted type-certificate shall include in addition the applicable operational suitability data certification basis, the operational suitability data and the type-certificate data sheet for noise. The aircraft type-certificate and restricted type-certificate data sheet shall include the record of CO2 emissions compliance, and the engine type-certificate data sheet shall include the record of exhaust emissions compliance.
Quoted word for word from Regulation (EU) No 748/2012, Easy Access Rules for Initial Airworthiness, 27 Nov 2025 revision.
The sentence includes the type design, the operating limitations, the instructions for continued airworthiness, and the type-certificate data sheet for airworthiness and emissions. For an aircraft type-certificate or restricted type-certificate, it also includes the operational suitability data and the type-certificate data sheet for noise. The library text still runs the words UAS orthe together. The quote keeps that spelling.
Making operational suitability data available
The holder of the type-certificate or restricted type-certificate shall make available:
(a)at least one set of complete operational suitability data prepared in accordance with the applicable operational suitability certification basis, to all known EU operators of the aircraft, before the operational suitability data must be used by a training organisation or an EU operator; and
(b)any change to the operational suitability data to all known EU operators of the aircraft; and
(c)on request, the relevant data referred to in points (a) and (b) above, to:
1.the competent authority responsible for verifying conformity with one or more elements of this set of operational suitability data; and
2.any person required to comply with one or more elements of this set of operational suitability data.
Quoted word for word from Regulation (EU) No 748/2012, Easy Access Rules for Initial Airworthiness, 27 Nov 2025 revision.
An operator's maintenance programme is not this point. It is covered in the aircraft maintenance programme guide.
The type-certificate holder after entry into service
The type-certificate holder keeps responsibilities once aircraft are in service. Under 21.A.3A(a), it must maintain a system for collecting, investigating and analysing occurrence reports, including failures, malfunctions, defects, errors, near misses and hazards. It must make information about that system and how to report available to known operators. Occurrences related to the approved product that have resulted or may result in an unsafe condition must be reported to the Agency.
Airworthiness directives bring a further responsibility for the holder. The Agency issues the directive; point 21.A.3B(c) sets out the holder's part when one has to be issued to correct an unsafe condition or require an inspection:
(c)When an airworthiness directive has to be issued by the Agency to correct the unsafe condition referred to in point (b), or to require the performance of an inspection, the holder of the type-certificate, restricted type-certificate, supplemental type-certificate, major repair design approval, ETSO authorisation or any other relevant approval deemed to have been issued under this Regulation, shall:
1.propose the appropriate corrective action or required inspections, or both, and submit details of these proposals to the Agency for approval; and
2.following the approval by the Agency of the proposals referred to in point 1, make available to all known operators or owners of the product, part, appliance, UAS, CMU or CMU component and, on request, to any person required to comply with the airworthiness directive, appropriate descriptive data and accomplishment instructions.
Quoted word for word from Regulation (EU) No 748/2012, Easy Access Rules for Initial Airworthiness, 27 Nov 2025 revision.
From type design to an individual aircraft
A type certificate approves a design. It is not itself the certificate for one airframe. Who manufactures to that design is the production-organisation guide. This point is the procedure for the certificate of one aircraft.
This Subpart establishes the procedure for issuing airworthiness certificates to aircraft which conform to a type certificate that has been issued in accordance with this Annex.
Quoted word for word from Regulation (EU) No 748/2012, Easy Access Rules for Initial Airworthiness, 27 Nov 2025 revision.
The certificate of airworthiness goes to an aircraft that conforms to a type certificate issued under this Annex. The certificate and the permit to fly are the subject of their own guide.
Applying for the aircraft's certificate
Under 21.A.172, the person in whose name the aircraft is or will be registered in a Member State, or their representative, is eligible to apply.
(a)Pursuant to point 21.A.172, an application for an airworthiness certificate shall be made in a form and manner established by the competent authority of the Member State of registry.
Quoted word for word from Regulation (EU) No 748/2012, Easy Access Rules for Initial Airworthiness, 27 Nov 2025 revision.
For a new aircraft, 21.A.174(b)(2) calls for a statement of conformity through one of the specified routes, a mass and balance statement for the current configuration where applicable, and a flight manual where the type-certification basis requires it. The application also identifies the class of certificate sought. Used aircraft have a separate documentation route under point (b)(3); their existing certificate position determines which documents accompany the application.
For a new aircraft, 21.B.326 also requires the authority to be satisfied that it conforms to an approved design, is in a condition for safe operation and complies with the applicable CO2 emissions requirements at first issuance. The certificate-of-airworthiness guide follows the application documents and permit-to-fly route in detail.
Into service
After that individual certificate, the aircraft enters the continuing-airworthiness guides, starting with Airworthiness Reviews and the ARC.
Where to read it yourself
The initial-airworthiness rules quoted here are in Regulation (EU) No 748/2012, in the EASA Easy Access Rules for Initial Airworthiness and Environmental Protection. Every citation in this guide was checked against the 2025-11-27 revision. The companion guides go into certification specifications and ETSO, type certification, design and production organisations, certificates of airworthiness, and parts and the EASA Form 1.
Educational content, not regulatory compliance advice. Verify against the current regulation text before relying on it.
In this series
Frequently asked questions
What is the difference between a type certificate and a certificate of airworthiness?
A type certificate approves the design, while a certificate of airworthiness belongs to an individual aircraft that conforms to a type certificate issued under Part-21. The type certificate includes the type design, operating limitations, instructions for continued airworthiness and the relevant type-certificate data sheets.
Who receives operational suitability data from the type-certificate holder?
The holder must make a complete set of operational suitability data and any changes available to all known EU operators of the aircraft. Under 21.A.62, the complete set must be available before it must be used by a training organisation or EU operator. Relevant data must also be supplied on request to the responsible competent authority and persons required to comply with it.
What occurrence reporting duties continue after a type certificate is issued?
The type-certificate holder must maintain a system for collecting, investigating and analysing occurrence reports and make reporting information available to known operators. Under 21.A.3A(a), it must report to the Agency occurrences related to the approved product that have resulted or may result in an unsafe condition.
What must a type-certificate holder do when an airworthiness directive is required?
When the Agency has to issue an airworthiness directive to correct an unsafe condition or require an inspection, the holder must propose corrective action, inspections or both for Agency approval. Under 21.A.3B(c), after approval it must provide descriptive data and accomplishment instructions to all known operators or owners and, on request, anyone required to comply.
Who can apply for an aircraft certificate of airworthiness?
The person in whose name the aircraft is or will be registered in a Member State, or their representative, is eligible to apply under 21.A.172. The application must follow the form and manner established by the competent authority of that Member State of registry.
What documents accompany a new aircraft's certificate of airworthiness application?
A new aircraft's application needs a statement of conformity through one of the routes in 21.A.174(b)(2), a mass and balance statement for its current configuration where applicable, and a flight manual if the type-certification basis requires one. The application must also identify the class of airworthiness certificate sought.
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Written by Dionysis Kefalas. Retired Hellenic Air Force Captain and founder of Avioverse. About the author
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