Flight data recorders (FDR)
Flight data recorders (FDRs), often referred to as "black boxes," are devices installed on aircraft to record essential flight data, including flight paths, altitude, airspeed, and crew actions. Initially conceptualized in the 1940s, the first functional FDR was developed by David Warren in 1957. These devices have greatly enhanced the ability of investigators to discern the causes of aviation accidents, providing vital information to families of victims and helping aviation authorities enact safety improvements.
FDRs are designed to withstand extreme conditions, including high temperatures and impact forces, which ensures that crucial data can be retrieved even after a crash. Modern FDRs have evolved to record a broader range of flight parameters through advanced solid-state technology, allowing for longer data retention and faster access to recorded information. In the United States, the Federal Aviation Administration (FAA) regulates FDR standards, mandating that they capture at least eighty-eight flight parameters.
While traditionally viewed as post-incident analysis tools, there is ongoing discussion in the aviation community about the potential for real-time data transmission from aircraft to enhance in-flight safety. Despite these considerations, FDRs remain integral to accident investigations, contributing to ongoing efforts to improve air travel safety across the globe.
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Subject Terms
Flight data recorders (FDR)
DEFINITION: Devices carried on aircraft that record information about flight paths and the actions of crew members.
SIGNIFICANCE: The presence of flight data recorders on aircraft has significantly improved the ability of investigators to determine the causes of airplane crashes. These devices have allowed investigators to provide the families of crash victims with clearer information about their loved ones’ deaths and have also enabled the agencies concerned with air travel to take corrective actions that have decreased the incidence of crashes and kept consumer confidence in air travel high.
The idea of placing devices on aircraft to record flight data originated in the 1940s, but it was not until 1957 that David Warren, an aeronautical researcher in Australia, created a flight data recorder (FDR) that could record all of an aircraft’s basic operating systems, including heading, altitude, time, airspeed, and vertical accelerations. The FDR was called the “red egg” at the time because of its bright reddish-orange color; it later, strangely, became known as the “black box.” This now-common term has been reported to have come into use after a journalist called the device a “wonderful black box,” but many also believe that the black box name came about because some of the original FDRs were painted black or because after an airplane crash the box is typically charred black.
The first patent issued for an FDR in the United States was granted to James Ryan in 1963. In 1965, all commercial airlines were required to install cockpit voice recorders that could capture the last thirty minutes of crew voice communications and noise on any flight. By the 1970s, major airlines began replacing these basic FDRs with more advanced systems, including magnetic tape recorders to replace the original foil recorders and more fire- and crash-resistant technology. As planes became larger and more technologically advanced, FDRs were developed to record increasing amounts of information, including data on engines and flaps.
During the 1990s, with the rapid advancement of computer technology, airlines began replacing magnetic tape recorders with solid-state FDRs that could store information on integrated circuits involving memory chips. Compared with earlier FDRs, these solid-state systems allowed for the recording of much longer intervals of data, required less overhaul and maintenance time, and enabled much faster retrieval of the information stored.
In the United States, regulations regarding FDRs are established and enforced by the Federal Aviation Administration (FAA); in Europe, these duties are fulfilled by the European Organization for Civil Aviation Equipment. In 1997, the FAA required that all FDRs on US planes must be capable of recording at least eighty-eight flight parameters. Modern FDRs record a much greater volume of information than their predecessors, including data on fuel flow, magnetic heading, control column, wheel position, and horizontal stabilizers.
How FDRs Work
The memory boards inside FDRs are protected by sheets of aluminum housing and dry silica insulation contained within stainless-steel shells. FDRs are typically placed in the tails of planes because this positioning provides them the most protection during crashes. The bright orange color and fluorescent tape on FDRs aids in their location after crashes. In addition, FDRs are equipped with underwater location beacons that send out ultrasonic pulses that can be detected by sonar. These beacons are activated when the devices touch water, and the pulses are sent out continuously for thirty days.
FDRs must go through rigorous survivability testing, including pressure tests, crash impact tests (which often involve shooting the devices from cannons), and trauma tests (which involve the dropping of heavy steel pins on the devices). Finally, FDRs are fire tested; they must be able to survive one hour at 1,100 degrees Celsius and another ten hours at 260 degrees Celsius.
Following an airplane crash in the United States, the FDR is located and then turned over to investigators of the National Transportation Safety Board (NTSB), who take it apart and download the data. When an FDR is badly damaged, its memory boards have to be removed and connected to special software that retrieves the data. Typically, experts are brought in to interpret the data, a process in which they compare movements of the plane and its instruments with the cockpit voice recordings. This process can take weeks or even months as investigators attempt to piece together failings in the operating system with the crew members’ words, as well as the damage to the aircraft.
Aeronautical researchers are always working to improve FDRs, and some now make video recordings of aircraft and their critical mechanical systems. Attempts are also constantly under way to increase the number of flight parameters recorded by FDRs in all aircraft, to improve the damage protection of FDRs themselves, and to place updated FDRs in small aircraft.
Some investigators have begun to view the FDR as a reactionary tool; they have suggested that it would be better to use satellite systems to provide instant access to information from aircraft that are having difficulty while they are in the air rather than after crashes have occurred. This is not likely to occur anytime in the near future, however; FDRs will probably remain critical in crash investigations rather than during in-flight emergencies.
Bibliography
Bibel, George. Beyond the Black Box: The Forensics of Airline Crashes. Baltimore: The Johns Hopkins University Press, 2007.
Byrne, Gerry. Flight 427: Anatomy of an Air Disaster. New York: Springer, 2002.
Faith, Nicholas. Black Box: The Air-Crash Detectives—Why Air Safety Is No Accident. Osceola, Wis.: Motorbooks International, 1997.
Tyagi, Vishesh. "Role of Forensic Science in Air Accident Investigation." Journal on Contemporary Issues of Law (JCIL), vol. 7, no. 2, 9 June 2023, jcil.lsyndicate.com/wp-content/uploads/2023/06/09.-ROLE-OF-FORENSIC-SCIENCE-IN-AIR-ACCIDENTS-INVESTIGATION.pdf. Accessed 15 Aug. 2024.
Witham, Janice. Black Box: David Warren and the Creation of the Cockpit Recorder. Sydney, N.S.W.: Lothian Books, 2006.