The History and Use of Flight Data Recorders, Research Paper Example

The Flight Data Recorder –popularly known as “the Black Box”- is sometimes on of the few identifiable items found in the wreckage of an airplane crash. Flight Data Recorders  (FDRs) have been in use for decades, though the technology utilized to record flight data has evolved over time, from relatively primitive devices to contemporary recording systems that take advantage of the most advanced digital technology. For many years, aircraft carried a single Black Box, though more recently two separate devices are used: the Flight Data Recorder and the Flight Voice Recorder (FVR). The popular nickname for Flight Data Recorders is a bit misleading; contemporary FDRs and FVRs are typically painted bright orange or bright red, to help make them visible in the aftermath of a crash (L3.com, 2011).

A plane crash in India in 1953 spurred the development of the first FDR. David Warren, a researcher from Australia, was investigating the site of the 1953 crash, and found himself frustrated by the lack of available information. This frustration prompted Warren to develop a series of FDR prototypes over the next few years; by the end of the 1950s, FDRs were in widespread use. In 1960 the Federal Aviation Administration (FAA) made FDRs mandatory on all commercial aircraft (Suddath, 2009).

The original technology used in FDRs was quite primitive by current standards –and even by the standards of the 1950s. Utilizing a system that was barely more advanced than Thomas Edison’s wax cylinders, the first FDRs contained strips of thin foil. A needle scratched grooves into these strips in real-time, encoding very basic data:  an aircraft’s altitude, speed (both forward speed and the speed of vertical movements), the direction in which it was traveling, and the current time (L3.com, 2011). Despite the simplicity of the early FDR technology, the nickname “Black Box” caught on in general use; this was not a reference to the color of the FDR itself, but to its mysterious and unseen contents (Suddath, 2009). The earliest FDRs were usually installed in the landing-gear wells, connected to the primary controls and instrumentation. After several crashes that caused damage to FDRs, they were moved to the rear of most aircraft where damage was least likely to occur (Phillips, 1997)..

There were some efforts to create FDRs earlier than Warren’s prototypes, though most failed because the “box” itself –the casing that housed the recoring device- simply could not withstand any significant crashes. FDRs were further hampered in their earliest days because of the limited usefulness of the basic information they recorded; despite these limitations, some FDRs were only capable of recoding such basic information as recently as 1987 (Suddath, 2009). The technology used to create the casing was of paramount importance, though, as the best recording technology in the world was useless if it was unprotected in a crash. Most aircraft make use of current or recent technology in their FDRs, but there are some older aircraft that still make use of the original “foil strip” FDRs.

By the mid-1960s, FDRs with tape-recording systems began to replace the first generation of FDRs. These newer systems recorded information to magnetic tape; the first wave of these devices were used to record the conversation among crew members and between the crew and air traffic controllers. Known as Cockpit Voice Recorders (CVRs), these devices would record the last thirty minutes of speech and other sounds leading up to a crash. The technology used for these new CVRs was adapted for use in FDRs as well; with the arrival of the magnetic-tape FDRs, more information about a flight could be recorded (L3.com, 2011). Along with the main parameters captured by first-generation FDRs, they could now record a range of information about the mechanical operation of the aircraft, such as the position of wing flaps, the functionality of landing gear and the condition of the engines at the time of a crash Suddath, 2009).

Tape-based FDRs remained the norm for years, though by the 1990s they were supplanted by Solid-State Recorders Flight Data Recorders (SSFDRs). These SSFDRs utilized digital circuitry instead of the moving parts needed to operate tape-based systems.  In the case of SSFDRs, data is encoded into the circuitry, and in the event of a crash, this data is less likely to be compromised and more easily recovered than data recorded to tape (L3.com). Along with advances in the recording capabilities of FDRs came advances in the design of their external shells; these advances made the casings more resistant to fire, air and water pressure, and impact damage. The growth of the recording technology allowed investigators to access data almost immediately, and CVRs were able to record for greater lengths of time, expanding from 30 minutes to 120 minutes by the mid-90s (Suddath, 2009).

Contemporary FDRs that record a wider array of data can be used for more than just investigating crashes; the constant monitoring of nearly every data-point during a flight allows investigators to learn not just went wrong in the event of a crash, but to learn what          goes right during safe, uneventful flights (Suddath, 2009). This new wealth of information helps pilots fly more safely and helps designers and engineers build safer aircraft.

The existence and use of FDRs is well-known by the general public. Many crashes generate a significant amount of news coverage, and the search for the FDR is often as closely monitored by journalists as it is by investigators (Suddath, 2009). Aircraft that have crashed at sea can pose a serious challenge to those charged with the location and recovery of the FDR, as can crashes that take place in remote or rugged terrain. Prompted by the challenges rescue and recovery teams often face, FDR designers began installing radio beacons inside the devices to make them easier to locate (L3.com).

The existence of this radio beacon does not always assure that it will be useful in locating the FDR after a crash. The signal from the typical FDR beacon is designed to broadcast for approximately 30 days; after that time, the signal becomes weak and then disappears completely.  In some instances, the radio beacon has helped to recover FDRs fairly quickly, both on land and in the ocean. In other instances, the radio beacon gives out long before the FDR is recovered.  In 1987, South African Airlines Flight 747 crashed into the ocean on a flight between Taiwan and Johannesburg, South Africa; the FDR remained undiscovered for over a year before being discovered by investigators. Of the several dozen commercial aircraft that have crashed into the sea since the advent of FDRs, only one remained missing as of 2009 (Suddath, 2009).

A 2009 article in TIME magazine recounts some infamous aircraft incidents during which the FDR captured compelling information. In 1990, a pilot aboard a British Airways flight was nearly pulled out through a broken windshield; with the aid of a flight attendant and a co-pilot pulling him in by his legs and torso, he survived the incident. In 1994, a pilot of an Aeroflot airplane had his two children in the cockpit, and allowed each of them to take a turn at the controls. After the 12-year-old girl had a turn, her brother took over. His voice can clearly ne heard on the CVR as he asks his father for permission to turn –right before the plane slams into a mountainous region of Siberia (Suddath, 2009).

As the author of the TIME article rightly notes, one of the most infamous recordings ever recovered from a CVR is that of United Flight 93 on September 11, 2001. The plane had been taken over by a team of hijackers; investigators later announced that the hijacked aircraft was headed for the Capitol Building in Washington, D.C.; the hijackers intended to crash the plane into the building in the same manner as two other planes struck the World Trade Center earlier that morning. On the CVR, the voices of the hijackers can be heard as they issue commands to the passengers; soon after the voices of several passengers can be heard as they enter the cockpit and overwhelm the hijackers. Moments later, the plane crashed into an unpopulated field, sparing the Capitol Building (Suddath, 2009). The public would learn later that some passengers had been in touch with family and loved ones before they rushed the hijackers; they were aware of the attacks on the World Trade Center, and sacrificed themselves to spare more lives on the ground.

As the technology utilized in FDRs has advanced, the required number and type of data points has expanded as well. Periodic adjustments and updates are issued by the FAA to ensure that aircraft are using the most up-to-date technology available. (Anon., 2011). With very few exceptions,  nearly all “turbine-powered” aircraft are required to carry a Flight Data Recorder onboard (Phillips, 1997).  Where FDRs once recorded a mere five points of data, the most advanced contemporary FDRs record nearly a hundred simultaneous sets of information. In addition to the basic bits of information, such as speed and altitude, FDRs now record everything from the hydraulic fluid levels in the wingflaps to dozens of measurements of engine function to the thickness of ice as it forms on the wings (faa.gov). Not all data points are needed for (or even available on) all types of aircraft, but the chances are quite good that if it flies, it has a Flight Data Recorder.

While the technology found in FDRs has come a long way in the last half-decade, the basic principles that spurred their creation remains the same: those responsible for designing and flying aircraft, as well as those responsible for determining what went wrong in the event of a crash, constantly seek as much useful information about their flights as possible. For anyone who has ever flown, will ever fly, or knows someone who will do either, the invention of the Flight Data Recorder remains invaluable. With these devices, we do not just learn what contributed to or caused a crash; more importantly, we often discover ways in which such tragedies can be avoided in the future.

Bibliography

Anon. “FAA federal aviation regulations.” Retrieved online 16 September 2011.

Faa.gov. “CFR final rule.” Retrieved online 16 September 2011.

L3.com. “History of flight recording.” Retrieved online 16 September 2011. http://www.l-3ar.com/html/history.html

Phillips, D. “FAA sets new flight regulations for black boxes.” Washington Post 11 July 1997.

Suddath, C. “Black boxes.” TIME Magazine. 02 July 2009.