Aviation Certification: FAA Needs to Strengthen Its Design Review Process for Small Airplanes

In 2020, FAA was in the midst of a major change in how it reviewed and certified the designs of small airplanes. For decades, FAA required that designs for small airplanes meet requirements specified in federal regulations. In December 2016, FAA issued a final rule to replace its prescriptive design requirements with performance-based regulations (Amendment 64 regulations). Performance-based regulations state requirements in terms of required results but do not prescribe a specific method for achieving the required results. Applicants must show how their design complies with each performance-based regulation by using a "means of compliance," which is a detailed design standard that, if met, accomplishes the safety intent of the regulation. FAA staff must review and accept an applicant's proposed means of compliance, which includes determining that the means of compliance shows the design meets the safety intent of the regulations. In 2020, GAO reported that FAA staff had faced various challenges conducting certification reviews, due in part to a lack of guidance addressing issues created by Amendment 64's new approach. FAA officials told GAO there was not a formal feedback mechanism to gather input from aircraft certification office staff and others on the implementation of Amendment 64. GAO noted that when implementing agency reforms, one leading practice is to develop a two-way continuing communications strategy that enables management to collect and respond to employee feedback regarding the effects of potential reforms. Developing a strategy to regularly solicit and respond to employee feedback regarding implementation of Amendment 64 would enable FAA to continuously address emerging issues and share information with staff tasked with implementing Amendment 64. Therefore, GAO recommended that the Executive Director of the Aircraft Certification Service implement a strategy to regularly collect, address, and share information and guidance resulting from employees' feedback regarding implementation of Amendment 64. In 2023, GAO confirmed that FAA had implemented a strategy to regularly solicit and respond to employee feedback regarding implementation of Amendment 64. In September 2022, FAA developed a feedback form for employees working on Amendment 64 projects to submit, which includes questions on how beneficial Amendment 64 was to the project, whether certain issues came up during the review, and an option to leave open-ended feedback and suggestions on Amendment 64. FAA officials ask staff to submit the form when they complete an Amendment 64 review, but staff can also submit it anytime. FAA also provided documentation of multiple outreach meetings held with FAA staff from 2020 through 2022, as well as planned sessions for 2023, which included discussion of Amendment 64 as well as updated information and guidance on the Amendment 64 process based on feedback provided by employees. Through these efforts, FAA is better positioned to help ensure that aircraft certification office staff have the necessary direction to implement Amendment 64 consistently and efficiently.

In 2020, FAA was in the midst of a major change in how it reviews and certifies the designs of small airplanes. For decades, FAA required that designs for small airplanes meet requirements specified in federal regulations. In December 2016, FAA issued a final rule to replace its prescriptive design requirements with performance-based regulations (Amendment 64 regulations). Performance-based regulations state requirements in terms of required results but do not prescribe a specific method for achieving the required results. Typically, FAA staff in the aircraft certification offices determine whether a product complies with applicable regulatory standards and approves products for certification by issuing a type certificate, amended type certificate, or supplemental type certificate (depending on the circumstances). FAA's Small Airplanes Standards Branch (SASB) was responsible for overseeing the implementation of Amendment 64. In 2020, GAO reported that although SASB officials said that they oversee and standardize implementation of Amendment 64 by being aware of and assisting aircraft certification office staff with all Amendment 64 design certifications, SASB did not have a method to identify all Amendment 64 certifications under review. SASB officials told GAO that they become aware of Amendment 64 design certifications through FAA's Certification Project Notification system (notification system). This notification system informs FAA offices of applications for type certificates, supplemental type certificates, and amended type certificates. However, the notification system did not identify the certification basis for applications. The certification basis defines the applicable amendment to 14 C.F.R. Part 23 for which the applicant must show compliance, e.g., Amendment 64 or another amendment. Thus, SASB could not identify the certification basis for supplemental type certificates and amended type certificates without contacting staff across the various offices to manually compile this information. Standards for Internal Control in the Federal Government states that management should design a process that uses the entity's objectives and related risks to identify the information requirements needed to achieve the objectives and address the risks. SASB officials acknowledged that they may not be aware of all Amendment 64 amended and supplemental type certifications but stated that they believed FAA staff or applicants would contact them if problems arose. However, without reliable information on the number of Amendment 64 supplemental type certificates and amended type certificates-which SASB estimated made up more than half of the in-process and completed certifications at the time of GAO's review-SASB lacked awareness of all Amendment 64 design certifications and thus cannot be sure it is providing assistance to all design certifications. Therefore, GAO recommended that the Executive Director of the Aircraft Certification Service implement a method to track Amendment 64 projects by certification basis. In 2024, FAA provided GAO documentation showing that it had updated its notification system so that staff in the aircraft certification office can indicate whether a project is an Amendment 64 project, as well as whether it is an amended or supplemental type certificate. By including this field, SASB officials are able to track Amendment 64 projects by certification basis, as needed.

In 2020, FAA was in the midst of a major change in how it reviewed and certified the designs of small airplanes. For decades, FAA required that designs for small airplanes meet requirements specified in federal regulations (contained in 14 C.F.R. Part 23 and referred to as Part 23 regulations). In December 2016, FAA issued a final rule to replace its prescriptive design requirements with performance-based regulations (Amendment 64 regulations). Performance-based regulations state requirements in terms of required results but do not prescribe a specific method for achieving the required results. One way that applicants can demonstrate to FAA staff that their proposed design meets the safety intent of the Amendment 64 regulations is by showing that the design complies with FAA-accepted industry consensus standards. Consensus standards are technical specifications developed by organizations such as ASTM International, an internationally recognized standards-development organization. In 2020, GAO reported that FAA faced some challenges in its implementation of performance-based regulations for small airplanes. Aircraft certification office and Small Airplanes Standards Branch (SASB) staff told GAO they have faced various challenges conducting certification reviews, due in part to a lack of guidance addressing issues created by Amendment 64's new approach. Many aircraft certification office and SASB staff GAO interviewed said additional guidance is needed regarding how to review applicants' proposed means of compliance . For example, ASTM consensus standards do not always have clear one-to-one links with Amendment 64 regulations, and staff are unsure of the level of detail applicants need to provide when citing which ASTM standards (or which portions of a standard) they are using for a means of compliance. In its final rule amending Part 23, FAA noted that to ensure performance-based standards were implemented consistently and correctly, FAA needed to develop guidance materials and provide sufficient information for staff. GAO has noted the importance of agencies' ensuring that staff have the information they need to achieve the agencies' objectives . Therefore, GAO recommended that the Executive Director of the Aircraft Certification Service provide information to help staff link ASTM consensus standards to Amendment 64 regulations. On March 11, 2022, FAA accepted the ASTM Top Level Specification F3264-21, which, according to FAA, provides direct linkage from the Amendment 64 regulations to the applicable ASTM consensus standards. In addition, FAA's March 11, 2022, acceptance document included a table to show the linkage from each Amendment 64 regulation to the applicable ASTM consensus standard . This information will help staff link ASTM consensus standards to Amendment 64 regulations.

In 2020, FAA was in the midst of a major change in how it reviews and certifies the designs of small airplanes. For decades, FAA required that designs for small airplanes meet requirements specified in federal regulations (contained in 14 C.F.R. Part 23 and referred to as Part 23 regulations). In December 2016, FAA issued a final rule to replace its prescriptive design requirements with performance-based safety regulations (Amendment 64 regulations). Performance-based regulations state requirements in terms of required results but do not prescribe a specific method for achieving the required results. Applicants must show how their design complies with each performance-based regulation by using a "means of compliance," which is a detailed design standard that, if met, accomplishes the safety intent of the regulation. FAA staff must review and accept an applicant's proposed means of compliance, which includes determining that the means of compliance shows the design meets the safety intent of the regulations. In 2020, GAO reported that FAA's reviews of design certifications had faced delays and challenges partly due to a lack of guidance for staff responsible for reviewing airplane designs. Specifically, many staff from the Small Airplanes Standards Branch (SASB) and FAA's aircraft certification offices said additional guidance was needed on how staff should review applicants' proposed means of compliance under Amendment 64 regulations. The staff said that this guidance should include how the means of compliance should be documented, what level of detail is needed, and who should be responsible for approving the proposed means of compliance in various scenarios. While FAA provided some initial training on reviewing applicants' propose means of compliance, and stated that more was planned, this training was canceled due to the COVID-19 pandemic. Some staff stated that FAA's initial training was too general and that they need more in-depth guidance and information. Some staff said that the lack of guidance has led to difficulties, delays, and possible inconsistencies in processing applications, and increased uncertainty for both staff and applicants. Similarly, several industry representatives told us they felt that FAA staff were uncomfortable with the new approach and needed additional training and guidance. GAO has noted the importance of agencies' ensuring that staff have the information they need to achieve the agencies' objectives. Further, federal internal control standards note the importance of procedures and training in achieving an agency's objectives. Therefore, GAO recommended that the Executive Director of the Aircraft Certification Service should develop procedures for staff's review of applicants' proposed means of compliance under Amendment 64, including how the means of compliance should be documented, what level of detail is needed, and who should be responsible for approving the proposed means of compliance in various scenarios. In June 2022, FAA published the "Part 23 Amendment 23-64 Implementation Procedures Guide" to provide guidance for staff who are reviewing applicants proposed means of compliance under Amendment 64. The guidance shows how means of compliance should be documented and what level of detail is needed. In April 2023, FAA published a memorandum ("Delegation of Signature Authority within the Policy and Standards Division") that identifies technical section managers, as delegated by FAA's Aircraft Certification Service, as responsible for approving the proposed means of compliance in various scenarios. This guidance will help FAA staff address the challenges they are facing, thereby reducing potential delays and inconsistency in reviews while helping ensure airplane designs fulfill FAA's safety requirements.