Modern commercial aircraft contain sophisticated electronic systems that gather, process, and manage digital data on many aspects of flight. These data originate from various systems and sensors throughout the aircraft. The data range from pilot operations to the outputs of sensors and systems. Some of these data are continuously recorded by the aircraft’s digital flight data recorder to help investigators understand what happened if the aircraft is involved in an accident or a serious incident. Designed to survive crashes, flight data recorders typically retain the data recorded during the last 25 hours of flight. Rather than analyzing flight data only after an incident or accident, some airlines routinely analyze the flight data from regular flights. Their aim is to identify problems that occur in routine operations and to correct these problems before they become accidents or incidents. In its 1992 study for FAA, the Flight Safety Foundation coined the term “Flight Operational Quality Assurance” to describe this function. The Foundation defined FOQA as “a program for obtaining and analyzing data recorded in flight to improve flight crew performance, air carrier training programs and operating procedures, air traffic control procedures, airport maintenance and design, and aircraft operations and design.” FOQA has its origin in the use of flight data recorders as mandated by the Civil Aeronautics Administration in 1958. Although the first flight data recorders captured only six parameters, they were a valuable tool for reconstructing what had occurred preceding a crash. In addition to recording data to assist in crash investigations, some airlines began to monitor data recorded on routine flights. Initially, the monitoring systems captured airworthiness data, but over time they have expanded to include operational data. FOQA programs were first established in Europe and Asia, and only within the past few years have some U.S. airlines begun adopting such a system on a trial basis. At present, about 33 foreign airlines and 4 U.S. airlines—United, US Airways, Continental, and Alaska—have implemented FOQA or FOQA-type programs. (See app. I for more detailed background information on FOQA and U.S. airlines’ experience with these programs; see app. II for a list of airlines worldwide that have implemented FOQA programs.) As part of FAA’s strategy to achieve significant reductions in aviation accident rates despite the rapid increase in air travel anticipated over the next decade, in 1995 the agency initiated a FOQA demonstration project to promote the voluntary implementation of FOQA programs by U.S. airlines. The objective of such a program is to use flight data to detect technical flaws, unsafe practices, or conditions outside of desired operating procedures early enough to allow timely intervention to avert accidents or incidents. For example, identifying repeated instances of unstabilized approaches to a particular airport could help to define a new approach pattern less likely to lead to an accident under adverse conditions, or to improved pilot training. Such a system has potentially broad application to flight crews’ performance and training, aircraft operating procedures, air traffic control procedures, aircraft maintenance, and airport design and maintenance. Major airlines in Europe and Asia, as well as the U.S. airlines that have FOQA programs, are uniform in their support of the program. How FOQA Works. FOQA involves (1) capturing and analyzing flight data to determine if the pilot, the aircraft’s systems, or the aircraft itself deviated from typical operating norms; (2) identifying trends; and (3) taking action to correct potential problems. Airlines with FOQA programs typically use a device called a quick access recorder to capture flight data onto a removable optical disk that facilitates the data’s frequent removal from the aircraft. Periodically, the optical disks are removed from the aircraft, and the flight data are analyzed by the ground analysis system at a centralized location. The data are analyzed by a computer system that evaluates about 40 to 80 predefined events for deviations from the airline’s specified tolerance thresholds. For example, an event might be the descent rate during approach. Deviations of more than certain predetermined values, called “exceedances,” are flagged and evaluated by a monitoring team. After investigating these exceedances to determine their validity and analyzing them to understand possible causes, the monitoring team will propose and evaluate corrective actions. Periodically, airlines aggregate exceedances over time to determine and monitor trends. (For a more complete discussion of FOQA operations, see app. I.) The FOQA Demonstration Project. In July 1995, FAA initiated a 3-year, $5.5 million demonstration project to facilitate the start-up of voluntary airline FOQA programs and to assess the costs, benefits, and safety enhancement associated with such programs. FAA provided hardware and software to each of the three airlines—United, US Airways, and Continental—that have implemented FOQA programs according to the demonstration project’s requirements. FAA purchased quick access recorders to equip 15 Boeing 737 aircraft at each of the three airlines. FAA also purchased a ground analysis system—the computer hardware and software for analyzing and visualizing FOQA data—for US Airways and Continental. Because United already had purchased a ground analysis system that analyzes these data for other types of aircraft, FAA purchased for the airline the additional software needed to analyze FOQA data from 737s. For their part, these airlines funded the cost of obtaining supplemental type certification of the airborne equipment, the costs of installation and maintenance, and the cost of personnel to run and monitor the program. Alaska Airlines is the fourth U.S. airline to have begun a FOQA program, but it has only recently met the demonstration project’s requirement for an agreement on FOQA by the airline’s pilot union. Consequently, the project has not yet provided any equipment to the airline. Alaska Airlines, however, received quick access recorders and a ground analysis system from the FAA Structural Loads Program and uses this equipment to operate its FOQA program. (See app. III for more information on the Structural Loads Program.) Other airlines that are participating in the demonstration project and are considering the implementation of a FOQA program are America West, Delta, Northwest, Trans World, Southwest, Continental Express, and United Parcel Service. (See app. I for a detailed description of the FAA demonstration project.) As a research and development effort of the FOQA initiative, FAA is developing the Aviation Performance Measuring System, an advanced system for conducting automated analysis and research on FOQA data. (See app. III for a description of this system and FAA’s other related technical programs.) Rather than requiring airlines to implement FOQA, FAA has chosen to promote the initiative through a cooperative demonstration project in partnership with the industry. According to the demonstration project’s program manager, it would be premature for FAA to mandate FOQA at this time because U.S. aviation is still in the early stages of developing FOQA and is primarily in a learning mode. The program manager contends that a mandated program would stifle innovation, encounter substantial resistance from airlines and pilots, and most likely result in minimal compliance. Thus, at present, FAA is working with the industry to raise interest in the concept, facilitate the design and implementation of voluntary FOQA programs, provide financial and technical assistance, and foster innovation. The primary characteristic that distinguishes FOQA from other safety reporting programs, such as the Aviation Safety Reporting Program or Aviation Safety Action Programs, is that FOQA provides objective, quantitative data on what occurs during flights rather than what is subjectively reported by individuals. Instead of needing to rely on perceived problems or risks, FOQA yields precise information on many aspects of flight operations, and this information can be used to help objectively evaluate a wide range of safety-related issues. U.S. and foreign airlines have reported on previously unknown or suspected problems for which FOQA has provided objective information that resulted in corrective actions. One airline found through its FOQA program that more exceedances occurred during visual flying than during instrument flying. This finding prompted the airline’s flight-training managers to rethink the relative emphasis given visual and instrument flying in the airline’s training programs. Another airline’s FOQA analysis confirmed that the incidence of descent rate exceedances during approaches was significantly higher at a particular runway at a U.S. airport than at other runways. After investigating the problem, the airline concluded that the air traffic control approach had been set too high, requiring pilots to descend more steeply than usual during their final approach. When the airline shared its findings with FAA management, the approach was modified to correct this potential problem. For landings, some airports’ air traffic control procedures require pilots to approach high and fast and then descend steeply. These approaches can result from a number of factors, including noise abatement rules, traffic volume, terrain, or weather conditions. Although airline managers know about the situations from pilots’ reports, FOQA gives them the quantitative information to demonstrate the extent of this problem at the various airports. With these data in hand, managers can be more effective in addressing the problem and taking action to mitigate or eliminate risks. FOQA can also help airlines determine the frequency of certain occurrences rather than having to rely on human judgment, particularly for the level of maintenance required. Two examples of these types of occurrences are hard landings and exceedances in engine temperatures. Prior to FOQA, airlines generally relied on pilots’ judgment of the necessity for corrective action if a hard landing occurred or an engine overheated. FOQA, however, can provide better information on the amount of force the aircraft experienced during a hard landing. Similarly, FOQA gives more data on the engines’ temperatures and the duration of overheating in some aircraft than were previously available without FOQA. With these data, managers can make more informed decisions about whether the aircraft needs to be inspected to check for structural damage or whether an engine needs to be overhauled. U.S. and foreign airlines have reported that they have used FOQA analysis to identify a variety of potential safety problems and take corrective action to resolve or mitigate them.