How do aviation regulators certify that a particular aircraft is airworthy? How are airworthiness certificates issued, what is examined, and what does the process look like? Join us for the latest in our ab initio primer guides!
With the growth of a variety of new technologies, from advanced automation to artificial intelligence, low-boom aerodynamics to new methods of propulsion, and an entire new category of aircraft with advanced air mobility, eVTOLs, air taxis and more, airworthiness certification is at the forefront of aviation’s development.
New frameworks are required, including performance based regulations [PDF] and cross-discipline approaches, as well as partnerships with other organisations: government agencies like NASA, global certification peers, industry standards bodies like SAE, and research institutions.
“The FAA’s current regulations allow aircraft to meet our strict safety standards in innovative ways,” the regulator’s spokesperson Kiiva Williams tells us. “We use the same data-driven approach when evaluating these complex systems that has created the safest aviation system in the world.”
The legal airworthiness of a particular aircraft is based both on its type certification and its own airworthiness as an airframe, which is proven by its airworthiness certificate.
At its most basic, an airworthiness certificate is a document from a certifying regulator — like the US Federal Aviation Administration, whose processes we’ll use as an example — that authorises the bearer to operate a particular aircraft in flight.
That bearer is usually the registered owner of an aircraft or their agent, and the process remains a very paper-based one that is ripe for a substantial amount of digitalisation, with key challenges revolving around verification management and overall process digitalisation.
At present, the bearer submits an application to the regulator by contacting a local servicing office, of which there are ten across the US from Alaska to Atlanta and Boston to Los Angeles — which list only phone and postal mail contact details.
An FAA inspector or authorised representative will then determine whether the overall condition of the aircraft is safe to operate, with a hit-list of items for an example conventional aircraft including skin corrosion, window delamination or crazing, fluid leaks, tire wear, and so on. Evaluations would normally include an overall condition check and verification of the aircraft’s maintenance records, as well as an assessment of its make, model, age and type.
The FAA issues two types of certificate for an aircraft to its owner: a Standard Airworthiness Certificate and a Special Airworthiness Certificate.
Standard certificates — specifically, the FAA form 8100-2, which must be displayed in the aircraft — cover aircraft in several categories:
- normal
- utility
- acrobatic
- commuter
- transport
- manned free balloon
- special
Special certificates are issued for aircraft in specific categories that satisfy the requirements of specific legislation — for example, for the restricted category, that is 14 CFR § 21.185 — and include:
- primary, where aircraft are flown for pleasure and personal use
- restricted, which covers a variety of professional uses including agricultural, forestry, wildlife conservation, aerial surveying, patrolling (such as for pipelines or power lines), weather control, aerial advertising, and other operations authorised by the FAA
- multiple certificates
- limited category type certificates
- light sport aircraft, but not gyroplanes, kit-builds or a “transitioning ultralight like vehicle”
- experimental, including research/development, regulation compliance demonstrators, crew training, exhibition, air racing, market surveys, amateur-built or kit-built aircraft, and uncrewed aircraft
- special flight permits
- provisional, where the type certificate specifies special operations or operating limitations
“We apply this methodical, process-oriented, safety-first approach to all aircraft. When tailoring existing rules to a new concept such as eVTOLs, the FAA determines the certification requirements for the eVTOL’s design, production, airworthiness, and operation,” the FAA’s Kiiva Williams says, noting that “some certifications could require the FAA to issue special conditions or additional airworthiness criteria, depending on the type of project.”
When it comes to determining the categories, and indeed the certification of new kinds of aircraft “any new aircraft design has to meet rigorous FAA safety standards,” Williams concludes.
Author: John Walton
Published 21st July 2022
Image: evtol over Budapest, courtesy of Rolls Royce
;
