The Story of Airworthiness Approvals and Certifications

Airworthiness approvals and certifications define how aircraft are designed, certified, approved for operation, and maintained to ensure they remain airworthy throughout their service life. The process involves multiple regulatory requirements and organizational responsibilities, from the issuance of the Type Certificate (TC) to continuing airworthiness compliance.

Initial Airworthiness

Aircraft are designed following certification requirements derived from ICAO Annex 8: Airworthiness of Aircraft, which are applied through the regulatory system of the state of design. Compliance is demonstrated through design documentation review, analysis, and testing. The process culminates with the issuance of a Type Certificate (TC), which confirms that the aircraft design meets applicable initial airworthiness regulations. A TC is generally valid for the aircraft type indefinitely unless revoked, suspended, or surrendered.

Each individual aircraft receives a Certificate of Airworthiness (CofA) once it conforms to the approved type design. The CofA proves the aircraft’s airworthiness and is typically non-expiring, though it may be revoked or suspended if required. For aircraft transferred to other jurisdictions, an Export CofA is issued to comply with the regulations of the receiving state, while a consequent CofA is issued upon import and registration.

Operational Approvals: AOC and Operating License

Commercial air transport operations require two separate approvals:

1. Air Operator Certificate (AOC): safety authorization issued by the competent aviation authority (e.g., EASA member state authority or FAA) to authorize commercial air transport operations.

2. Operating License: economic authorization issued by the transportation authority (e.g., Ministry of Transport in EASA states, U.S. Department of Transportation for FAA operators) granting the airline the legal right to conduct commercial air transport, subject to financial and regulatory conditions.

The AOC is an unlimited approval, unless revoked or suspended, that authorizes the operator to conduct specific air transport operations, including defined types of operation, operational areas, and applicable limitations.

The Operations Specifications (Ops Specs) define the authorizations, conditions, and operational limitations for each aircraft type. The Ops Specs include the authorized specific approvals, such as PBN (Performance-Based Navigation), RVSM (Reduced Vertical Separation Minimum), LVO (Low Visibility Operations), and EDTO (Extended Diversion Time Operations, formerly ETOPS).

The Ops Specs also identify the person or organization responsible for maintaining the continuing airworthiness of the aircraft and reference the regulations that govern these responsibilities, such as EASA Part-CAMO (Continuing Airworthiness Management Organization).

Continuing Airworthiness

To maintain airworthiness, operators must ensure that:

• The CofA remains valid

• Maintenance is performed according to an approved Aircraft Maintenance Program (AMP)

The AMP is primarily derived from the Instructions for Continuing Airworthiness (ICA) issued by the Type Certificate holder and adapted to the operator’s specific operation.

Compliance approaches vary between EASA and FAA:

• EASA: Requires an approved Continuing Airworthiness Management Organization (CAMO). The validity of the CofA is verified through an Airworthiness Review Certificate (ARC).

• FAA: Does not recognize a CAMO system; operators implement their own Continuous Airworthiness Maintenance Program (CAMP).

The ARC review under EASA includes a detailed check of aircraft records, physical inspections, and compliance verification with Airworthiness Directives (ADs) and the approved AMP. The ARC is issued annually, although it can be extended twice for one-year periods each if the aircraft has been continuously managed by the same CAMO and maintained by an approved Part-145 maintenance organization during the preceding 12 months.

Maintenance and Certification

Maintenance compliance is formally documented through the Certificate of Release to Service (CRS). Supporting records, often called the dirty fingerprints, provide detailed descriptions of maintenance tasks, supporting data, and associated findings. The CRS is issued after maintenance tasks and before the next flight to certify that required work has been completed.

Certifying staff must hold the appropriate authorization for the aircraft type. For EASA operators, this is the Part-66 Aircraft Maintenance License (AML) with the applicable type rating. For FAA operators, this is the Mechanic Certificate. These credentials ensure staff are qualified to perform and certify maintenance on the specific aircraft type.

Certifying staff must hold the appropriate authorization for the aircraft type. For EASA operators, this is a Part-66 Aircraft Maintenance License (AML) with the applicable type rating. For FAA operators, it is a Part-65 Airframe and Powerplant (A&P) Certificate, supplemented with an inspection authorization for certain certification tasks.

Authorization to perform maintenance is provided by approved Part-145 maintenance organizations, and staff qualifications are verified through experience, training, and theoretical knowledge, either directly assessed by authorities or via approved Part-147 training organizations.

Shared Responsibility

While the legal responsibility for continuing airworthiness rests with the operator, practical responsibility is shared among several stakeholders, each contributing to maintaining safety and compliance:

• Manufacturer / Type Certificate Holder – provides the approved design and Instructions for Continuing Airworthiness (ICA).

• Operator – holds legal responsibility for continuing airworthiness and ensures compliance with Airworthiness Directives (ADs) and the Aircraft Maintenance Program (AMP). In EASA environments, these responsibilities are typically exercised through an approved Continuing Airworthiness Management Organization (CAMO).

• Maintenance Organizations (Part-145) – perform maintenance and issue Certificates of Release to Service (CRS).

• Certifying Staff – qualified personnel who carry out and certify maintenance tasks.

• Training Organizations (Part-147) – provide the theoretical and practical training required for qualified maintenance staff.

• Regulatory Authorities – issue certificates (TC, CofA, AOC) and oversee ongoing airworthiness, for example through the Airworthiness Review Certificate (ARC) in EASA.

Learn the essentials of continuing airworthiness and aircraft maintenance in practice →