The Federal Aviation Administration (FAA) should provide its employees with additional resources and guidance for evaluating proposed aircraft designs — including eVTOL designs — under the new, performance-based certification regulations of Part 23.
That’s according to the U.S. Government Accountability Office (GAO), which on Nov. 16 released a report on its investigation into how well the FAA has been implementing the regs that came into effect in 2017. While acknowledging that the FAA is still early in its implementation process, the GAO found the agency has faced delays and challenges in its initial design reviews under this new approach.
“FAA staff who perform design reviews expressed uncertainty about the level of detail that applicants need to provide when showing how their designs meet the new regulations,” the GAO report states. “According to the staff and GAO’s review, this and other challenges are partly due to a lack of guidance on how to address issues created by this new approach.”
The GAO is recommending that the FAA create relevant guidance for staff to clear up some confusion, and assess what resources it needs to effectively implement the new rules. The GAO also wants the FAA to develop performance measures to ensure that the revised regulations contained in Part 23 Amendment 64 are meeting their objectives with respect to safety and innovation.
As the GAO recounts, the regulatory changes were motivated by concerns that the prescriptive technical requirements in the previous version of Part 23 were making it too difficult to certify modern, safety-enhancing technologies in normal category airplanes — those with 19 passenger seats or less. Amendment 64 replaced those prescriptive standards with broadly worded performance-based regulations that specify the required outcomes, but not necessarily the details of how to get there.
“For example, FAA condensed 32 regulations that provided specific instructions on the design and placement of various instruments and equipment to one regulation that states (generally) that instrument markings must be displayed in a conspicuous manner and clearly indicate their function,” the GAO explains, noting that other regulators including the European Union Aviation Safety Agency (EASA) are also shifting to performance-based rules.
One consequence of this shift has been to open the door to certification of novel aircraft designs, including eVTOL aircraft for urban air mobility applications. With respect to such designs, the GAO notes, “FAA officials stated that while FAA is still determining which regulations they will use to certify the aircraft, they anticipate that some Part 23 regulations will apply.”
As part of its audit, the GAO interviewed one company that is undergoing the FAA certification process for a fly-by-wire eVTOL air taxi. According to the GAO’s report: “Company representatives told us that Amendment 64 regulations allowed them to develop and pursue certification of the aircraft more quickly than if performance-based certification regulations were not in effect in the United States. They added that if such regulations had not been in effect, then their company would have sought initial certification of the aircraft in another country.”
As of July 2020, the FAA said it had 11 type certificate applications under Part 23 Amendment 64 in process, and anticipated another four based on preliminary discussions with prospective applicants. The GAO report does not break down how many of these are urban air mobility vehicles, but the FAA recently indicated it has four active type certificate applications for eVTOL aircraft in the works.
Although the GAO found industry representatives and staff to be “generally supportive of the new approach” to certification, there have been some growing pains. For example, the FAA’s revised regulations allow applicants to use industry consensus standards — such as those issued by ASTM International — as means of compliance, but the FAA has been relatively slow to accept them and applicants have had to spend extra time demonstrating how ASTM standards map onto Amendment 64. One applicant told the GAO that it took two years for the FAA to fully approve its means of compliance.
Management and staff with the FAA’s Small Airplane Standards Branch (SASB) told the GAO that they have experienced delays and challenges reviewing ASTM consensus standards and unique means of compliance due to resource constraints. The GAO report warns that as ASTM continues to develop and revise its standards and the FAA receives more Amendment 64 applications presenting novel technologies, “it will be increasingly important for FAA to identify the resources necessary for it to perform timely reviews of consensus standards and proposed means of compliance.”
In the meantime, the GAO recommends, the FAA should develop various procedures and guidance to help its staff process applications, including information to help staff link ASTM consensus standards to Amendment 64 regulations. FAA and ASTM officials told auditors that ASTM is in the early stages of such an effort, which it expects to complete in 2021.
As of July 2020, the FAA had yet to complete a type certificate review under Amendment 64, making it difficult to evaluate the impact of the new regulations. However, neither has the agency developed any relevant performance measures. According to the GAO, “establishing performance measures for the Amendment 64 regulations would enable FAA to assess over time whether it is realizing the goals of the regulations — improving safety, reducing regulatory cost burden, and spurring innovation and technology.”
In its response to the report, the FAA’s parent agency, the U.S. Department of Transportation, says it concurs with the GAO’s recommendations and will provide a detailed response to those recommendations within 180 days.