Airworthiness - Aircraft Type Certification

Airworthiness - Aircraft Type Certification

In order to comply with international aviation law and operate on a commercial basis, a civil aircraft type must be certified by an appropriate regulatory authority to show that the design complies with airworthiness requirements.  For example, in the UK, this would be the Civil Aviation Authority (CAA), in the EU, it would be the European Union Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) in the United States.

Airworthiness requirements may include evidence of safety and environmental protection, demonstration of analysis, simulations, flight and ground tests (such as ensuring the aircraft structure can with withstand bird strikes and fatigue tests), along with novel or unusual design features.  On satisfactory completion of the certification activities, the regulatory authority issues a type certificate to the manufacturer.  

What does a type certificate cover?

The type certificate covers a specific aircraft design, meaning that any subsequent changes to the design would require the certification to be reviewed and re-issued, as necessary.  As well as the product design itself, the type certification also covers the maintenance programme sustaining the airworthiness of the aircraft while it is in-service.  

Aircraft that are manufactured to the certified design standard are individually assessed by the regulatory authority and each aircraft is issued with an airworthiness certificate, enabling it to be operated safely within the permitted operating envelope.

What happens if a design fault is found?

If a condition is found during service that presents an unacceptable risk, the certifying regulatory authorities will issue an airworthiness directive to all owners of that aircraft type, detailing actions that must be taken to address risk.  Endangering safety hazards and deficiencies are subject to mandatory reporting in the form of Mandatory Occurrence Reports (MORs).   The UK CAA receives, on average, over 30,000 MORs per year, many of which result in the issue of airworthiness directives.  

Can modifications be authorised by other organisations?

Modifications to an aircraft type can be made by an approved organisation other than the type certificate holder.  Such changes need to be certified via the issue of a supplementary (or supplemental) type certificate by the approved organisation.

What about military, experimental and light aircraft?

Military aircraft undergo a similar certification procedure, the detail of which will depend on the particular national military aviation regulatory regime; for example the Military Aviation Authority (MAA) in the UK.

Simpler procedures exist for experimental and privately-owned light aircraft.

Have compliance tools evolved to support a digital audit trail?

The process of certifying the original design, any subsequent design modifications and the monitoring of continuing airworthiness is extremely complex and ongoing and relies on the existence of a coherent set of ongoing evidence, covering not only the aircraft structure, but also engines, propellors, additional parts and equipment.  Such evidence will be produced and maintained by a wide variety of organisations involved with designing, manufacturing and operating the aircraft type. 

Evidence previously existed in the form of hard-copy documents and drawings, and while still accompanied by a few hand-written work orders, supporting information is now predominately in digital format.  Nonetheless, keeping track of all the evidence and ensuring compliance with the relevant regulatory requirements is extremely challenging and without which, equipment and platform availability and safety could be severely impacted.

The advent of cloud-based solutions that provide wide-area connectivity and controlled access to electronic information has made managing the ongoing body of certification evidence more straightforward but, given that the various regulatory bodies and approved organisations have differing requirements, it is important that information frameworks are tailored to meet specific certification circumstances.

These days, cloud software service providers make sure that their capabilities include a detailed understanding of their customers’ commercial environment as well as having the technical competence to develop configurable solutions.