Located in FAA’s Office of Aviation Safety, the Aircraft Certification Service (Aircraft Certification) and Flight Standards Service (Flight Standards) issue certificates and approvals for the operators and aviation products used in the national airspace system based on standards set forth in federal aviation regulations. FAA inspectors and engineers working in Aircraft Certification and Flight Standards interpret and implement the regulations governing certificates and approvals via FAA policies and guidance, such as orders, notices, and advisory circulars. Aircraft Certification’s approximately 950 engineers and inspectors in 38 field offices issue approvals to the designers and manufacturers of aircraft and aircraft engines, propellers, parts, and equipment, including the avionics and other equipment required for the Next Generation Air Transportation System (NextGen)—a federal effort to transform the U.S. national airspace system from a ground-based system of air traffic control to a satellite-based system of air traffic management. These approvals are issued in three areas: (1) design—including type certificates for new aircraft, engine, or propeller designs, amended type certificates (issued only to the type certificate holder) for derivative models, and supplemental type certificates for major changes to existing designs by either the type certificate holder or someone other than the original type certificate holder; (2) production—including production certificates, which certify a manufacturer’s ability to build an aircraft, engine, or propeller in accordance with an FAA-approved design, and parts manufacturer approvals for spare and replacement parts; and (3) flight approval—original airworthiness certificates and approvals for newly manufactured aircraft, engines, propellers, and parts. Aircraft Certification, along with Flight Standards, provides a safety performance management system intended to assure the continued operational safety of all aircraft operating in the national airspace system and of U.S.-built aircraft operating anywhere in the world. Aircraft Certification is also responsible for the appointment and oversight of designees and delegated organizations that play a critical role in acting on behalf of FAA to perform many certification and approval activities, such as the issuance of design and airworthiness approvals for aircraft parts. Since 2005, Aircraft Certification has used project sequencing to prioritize certification submissions on the basis of available resources. Projects are evaluated against several criteria, including safety attributes and their impact on the air transportation system. In fiscal year 2009, Aircraft Certification issued 4,248 design approvals, 2,971 production approvals, and 508 airworthiness certificates. Figure 1 shows the Aircraft Certification approvals issued for fiscal years 2005 through 2009. As of June 2010, according to FAA, Aircraft Certification had a backlog of 47 projects. (According to a senior FAA official, the number of approvals decreased from fiscal year 2006 to fiscal year 2007 because Aircraft Certification implemented a new data collection system in fiscal year 2007 that improved data collection definitions and processes.) Figure 2 contains key information about Aircraft Certification’s organization, and figure 3 indicates key phases in Aircraft Certification’s product approvals process. Flight Standards’ nearly 4,000 inspectors issue certificates allowing individuals and entities to operate in the national airspace system. Flight Standards also issues approvals for programs, such as training and minimum equipment lists. Flight Standards field office managers in over 100 field offices use the Certification Services Oversight Process to initiate certification projects within their offices. According to FAA, the field offices are also assisted by a headquarters-based office that provides experts on specific aircraft and airlines. Accepted projects are processed on a first-in, first-out basis within each office once FAA determines that it has the resources to oversee an additional new certificate holder. Flight Standards issued 599 air operator and air agency certificates in fiscal year 2009. These include certificates to commercial air carriers under 14 C.F.R. part 121, operators of smaller commercial aircraft under 14 C.F.R. part 135, repair stations under 14 C.F.R. part 145, and pilot schools and training centers under 14 C.F.R. parts 141 and 142, respectively. According to its Director, Flight Standards also issues over 6,000 approvals daily. Figure 4 shows the number of air operator and air agency certificates issued by Flight Standards in fiscal years 2005 through 2009. FAA officials noted that certification projects within and among the categories of air operators and air agencies require various amounts of FAA resources. For example, FAA indicated that an agricultural operator certification requires fewer FAA resources than a repair station certification. Additionally, certifications of small commercial aircraft operations that are single pilot, single plane require a different set of resources than operations that are dual pilot and/or fly more aircraft. As of July 2010, Flight Standards had 1,142 certifications in process and a backlog of 489 applications. According to an FAA official, Flight Standards has more wait-listed applications than Aircraft Certification because it receives numerous requests for certificates, and its certifications are substantially different in nature from those issued by Aircraft Certification. Flight Standards is also responsible for assuring the continued operational safety of the national airspace system by overseeing certificate holders, monitoring (along with Aircraft Certification) operators’ and air agencies’ operation and maintenance of aircraft, and overseeing designees and delegated organizations. Flight Standards inspectors were tasked with overseeing 13,089 air operators and air agencies, such as repair stations, as of March 2010. Unless assigned to a large commercial air carrier issued a certificate under part 121, a Flight Standards inspector is typically responsible for overseeing several entities that often perform different or several functions within the system—including transporting passengers, repairing aircraft, and training pilots. Figures 5 and 6 contain key information about Flight Standards’ organization and certification process for air operators and air agencies. Studies we reviewed and aviation stakeholders and experts we spoke with indicated that variation in FAA’s interpretation of standards for certification and approval decisions is a long-standing issue that affects both Aircraft Certification and Flight Standards, but the extent of the problem has not been quantified in the industry as a whole. Inconsistent or variant FAA interpretations have been noted in studies published over the last 14 years. A 1996 study by Booz Allen & Hamilton, conducted at the request of the FAA Administrator to assess challenges to the agency’s regulatory and certification practices, reported that, for air carriers and other operators, the agency’s regulations are often ambiguous; subject to variation in interpretation by FAA inspectors, supervisors, and policy managers; and in need of simplification and consistent implementation. A 1999 task force, convened at the request of the FAA Administrator to assess FAA’s certification process, found that the agency’s requirements for the various approvals—such as type certificates and supplemental type certificates—varied substantially because of differences in standards and inconsistent application of those standards by different FAA field offices. While FAA has put measures in place since these two reports appeared, a 2008 Independent Review Team, which was commissioned by the Secretary of Transportation to assess FAA’s safety culture and approach to safety management, found that a wide degree of variation in “regulatory ideology” among FAA staff continues to create the likelihood of wide variation in decisions within and among field offices. Industry officials and experts representing a broad range of large and small aviation businesses told us that variation in interpretation and subsequent decisions occurs in both Aircraft Certification and Flight Standards, but we found no evidence that quantified the extent of the problem in the industry as a whole. Specifically, 10 of the 13 industry group and individual company representatives we interviewed said that they or members of their organization experienced variation in FAA’s certification and approval decisions on similar submissions; the remaining 3 industry representatives did not raise variation in interpretations and decisions as an issue. For example, an official from one air carrier told us that variation in decisions occurs regularly when obtaining approvals from Flight Standards district offices, especially when dealing with inspectors who are newly hired or replacing a previous inspector. He explained that new inspectors often task air carriers to make changes to previously obtained minimum equipment lists or conformity approvals for an aircraft. The official further noted that inspector assignments often change for reasons such as transfers, promotions, or retirement and that four different principal operations inspectors were assigned to his company during the past 18 months. Experts on our panel and most industry officials we interviewed indicated that, though variation in decisions is a long-standing, widespread problem, it has rarely led to serious certification and approval process problems. Experts on our panel generally noted that serious problems with the certification and approval processes occur less than 10 percent of the time. However, when we asked them to rank certification and approval process problems we summarized from their discussion, they chose inconsistent interpretation of regulations, which can lead to variation in decisions, as the most significant problem for Flight Standards and as the second most significant problem for Aircraft Certification. Panelists’ concerns about variation in decisions included instances in which approvals are reevaluated and sometimes revised or revoked in FAA jurisdictions other than those in which they were originally granted. Industry officials we interviewed, though most had experienced it, did not mention the frequency with which variation in decisions occurred. However, 8 of the 13 said that their experiences with FAA’s certification and approval processes were generally free of problems compared with 3 who said they regularly experienced problems with the process. FAA’s Deputy Associate Administrator for Aviation Safety and union officials representing FAA inspectors and engineers acknowledged that variation in certification and approval decisions occurs. The Deputy Associate Administrator noted that variation in interpretation and certification and approval decisions occurs in both Aircraft Certification and Flight Standards. He acknowledged that a nonstandardized process for approvals exists and has been a challenge for, and a long-term criticism of, the agency.