The Airbus A321XLR was formally certified by the European Aviation Safety Agency (EASA) ahead of the Farnborough Airshow on July 19, 2024. The aircraft received its certificate of airworthiness, a vital document that allows the production of the aircraft to go ahead in earnest.
Bringing a new aircraft into service is a huge logistical challenge for manufacturers, culminating in the aircraft being certified as safe to fly in passenger service by a select aviation authority – enter the certificate of airworthiness. Let’s take a closer look at the ‘CofA’ and what it entails.
What is a Certificate of Airworthiness?
A Certificate of Airworthiness (CofA) is a crucial document issued by the national aviation authority of a country, such as the Federal Aviaton Authority (FAA) in the USA. This certificate confirms that an aircraft is airworthy and meets the safety standards set by the regulatory body.
Do they expire?
No – but an annual review is needed, this is called an Airworthiness Review Certificate, or ‘ARC’. The ARC is overseen by the national aviation authority in question (such as the United States FAA or UK Civil Aviation Authority), and entails a full documented review of the aircraft records and a physical survey of the aircraft.
What happens before the aircraft goes into production?
Stage Sub-Stage Details
1. Design & deveopment Concept and Preliminary Design The aircraft manufacturer develops initial designs and concepts. These designs must comply with international and national aviation standards.
Type Certificate Application The manufacturer applies for a Type Certificate (TC) from the aviation authority, demonstrating that the aircraft design meets all regulatory requirements.
2. Engineering and Safety Reviews Detailed Design and Analysis Detailed engineering designs are developed, including structural, aerodynamic, and systems analyses.
Compliance Documentation The manufacturer prepares documentation proving compliance with all applicable airworthiness standards and regulations.
Testing Plans Plans for necessary tests, including ground tests and flight tests, are submitted for approval.
3. Testing and Certification Structural testing Components and systems are tested on the ground to ensure they meet safety and performance standards.
System Functionality Tests All aircraft systems (e.g., avionics, hydraulics, electrical) undergo rigorous testing to ensure they function correctly under various conditions.
4. Flight testing Flight Test Program The aircraft undergoes a series of test flights to validate its performance, handling, and systems functionality.
Safety and Performance Verification Flight test data is analyzed to verify that the aircraft performs as expected and meets all safety standards.
Test Reports Detailed flight test reports are compiled and submitted to the aviation authority for review.
What happens after production begins?
Stage Sub-stage What happens
3. Production Production Certificate The manufacturer must obtain a Production Certificate, demonstrating that they can consistently produce aircraft that conform to the approved type design.
Quality assurance The manufacturer implements rigorous quality control processes during production to ensure each aircraft meets the approved design specifications.
4. Conformity Inspections Initial Inspections Aviation authority inspectors conduct initial inspections of production aircraft to ensure they conform to the approved type design and meet all regulatory requirements.
Continued Surveillance Ongoing inspections and audits are conducted to ensure continued compliance with airworthiness standards during production.
5. Post-Production Certificate of Airworthiness Application For each individual aircraft, the manufacturer or operator applies for a CofA from the aviation authority.
Inspection and Testing The aviation authority conducts a detailed inspection of the aircraft, reviewing documentation and conducting necessary tests to ensure it is airworthy.
Issuance of certificate of airworthiness If the aircraft meets all requirements, the Certificate of Airworthiness is issued, allowing the aircraft to enter service.
5. Continued Airworthiness Scheduled Maintenance Regular maintenance is conducted according to the manufacturer’s guidelines and regulatory requirements to ensure ongoing airworthiness.
Airworthiness Directives (ADs) The aviation authority may issue ADs requiring specific inspections, modifications, or repairs to address identified safety issues.
Continual Monitoring The aircraft’s operational data is continuously monitored, and any necessary corrective actions are taken to maintain airworthiness.
What happens when modifications or repairs are needed?
- Supplemental Type Certificates (STCs) are issued for any significant modifications. These are required to demonstrate that the modification complies with airworthiness standards. These are required when instigating changes such as installing WiFi systems, or modifying aircraft, engine, propeller, or other aircraft parts.
- Major repairs must be approved by the aviation authority to ensure they do not compromise the aircraft’s overall safety or airworthiness.
Boeing’s Certificate of Airworthiness woes
The certification process of the Boeing 737 MAX by the U.S. Federal Aviation Administration (FAA) faced significant scrutiny following two fatal crashes involving the aircraft. These incidents revealed critical flaws in the aircraft’s Maneuvering Characteristics Augmentation System (MCAS), which were not adequately addressed during certification. The relationship between Boeing and the FAA came under intense criticism, with allegations of excessive closeness and lapses in oversight. This perceived lack of rigorous independent evaluation led to widespread concerns about regulatory effectiveness and the safety of the certification process. The resulting public and industry backlash prompted a comprehensive review and overhaul of the FAA’s certification procedures to restore trust and ensure robust safety standards.
The certification of all Boeing 737 MAX family aircraft continues to face delays, though Max 8 and MAX 9 aircraft are permitted to continue flying whilst outstanding fixes are introduced.
The MAX 7 and 10 have not been so lucky. In January 2024, Boeing withdrew a safety exemption request for the 737 MAX 7 related to an anti-icing system issue that could lead to overheating of the inlet cowl. This problem also affected the MAX 10. Boeing has been working on a design modification to address this issue, and testing of the fix is expected to begin in late 2024.
The Boeing 777-9, part of the 777X family, has also faced delays. Initially planned for delivery in 2020, the timeline has been pushed back multiple times, with the current projection for late 2025. The aircraft began certification flight testing in July 2024, a crucial milestone in its journey towards certification.
The process of issuing a Certificate of Airworthiness is thorough and multifaceted, involving detailed design reviews, extensive testing, stringent quality control during production, and ongoing maintenance and monitoring. Each stage is crucial to ensure that the aircraft meets the highest safety and performance standards before it is certified for operation.
Cover photo: BremenPinguin, JetPhotos.
![An example full flight summary response from the Flightradar24 API: { "data": [ { "fr24_id": "0987654321", "flight": "SK1415", "callsign": "SAS1415", "operated_as": "SAS", "painted_as": "SAS", "type": "A20N", "reg": "SE-DOY", "orig_icao": "ESSA", "orig_iata": "ARN", "datetime_takeoff": "2023-01-27T05:15:22", "runway_takeoff": "12R", "dest_icao": "EKCH", "dest_iata": "CPH", "dest_icao_actual": "EPWA", "dest_iata_actual": "WAW", "datetime_landed": "2023-01-27T06:15:10", "runway_landed": "27L", "flight_time": 3600, "actual_distance": 1007.74, "circle_distance": 6245, "category": "Passenger", "hex": "4A91F9", "first_seen": "2023-01-27T05:06:22", "last_seen": "2023-01-27T06:18:10", "flight_ended": "true" } ] }](https://www.flightradar24.com/blog/wp-content/uploads/2025/04/Flight-summary-API-cover-300x148.jpg)
![An example full flight summary response from the Flightradar24 API: { "data": [ { "fr24_id": "0987654321", "flight": "SK1415", "callsign": "SAS1415", "operated_as": "SAS", "painted_as": "SAS", "type": "A20N", "reg": "SE-DOY", "orig_icao": "ESSA", "orig_iata": "ARN", "datetime_takeoff": "2023-01-27T05:15:22", "runway_takeoff": "12R", "dest_icao": "EKCH", "dest_iata": "CPH", "dest_icao_actual": "EPWA", "dest_iata_actual": "WAW", "datetime_landed": "2023-01-27T06:15:10", "runway_landed": "27L", "flight_time": 3600, "actual_distance": 1007.74, "circle_distance": 6245, "category": "Passenger", "hex": "4A91F9", "first_seen": "2023-01-27T05:06:22", "last_seen": "2023-01-27T06:18:10", "flight_ended": "true" } ] }](https://www.flightradar24.com/blog/wp-content/uploads/2025/04/Flight-summary-API-cover-768x378.jpg)
