Flight data recorder
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The flight data recorder (FDR) is a flight recorder used to record specific aircraft performance parameters. A separate device is the cockpit voice recorder (CVR), although some recent types combine both in one unit. Popularly, though almost always falsely, known as the black box used for aircraft mishap analysis, the FDR is also used to study air safety issues, material degradation, and jet engine performance. These ICAO regulated "black box" devices are often used as an aid in investigating aircraft mishaps, and its recovery is second only in importance to the recovery of victims’ bodies. The device's shroud is usually painted bright orange and generally located in the tail section of the aircraft.
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[edit] History
The first prototype FDR was produced in 1957 by Dr. David Warren of the then Aeronautical Research Laboratories of Australia. In 1953 and 1954, a series of fatal mishaps on the De Havilland DH106 Comet prompted the grounding of the entire fleet pending an investigation. Dr. Warren, a chemist specializing in aircraft fuels, was involved in a professional committee discussing the possible causes. Since there had been neither witnesses or survivors, Dr. Warren conceived of a crash survivable method to record the flight crew's conversation, reasoning they would likely know the cause.
Despite his 1954 report entitled "A Device for Assisting Investigation into Aircraft Accidents" and a 1957 prototype FDR called "The ARL Flight Memory Unit", aviation authorities from around the world were largely uninterested. This changed in 1958 when Sir Robert Hardingham, the Secretary of the UK Air Registration Board, became interested. Dr. Warren was asked to create a pre-production model which culminated in the "Red Egg", the world's first commercial FDR , made by the British firm of S. Davall & Son. The "Red Egg" got its name from its shape and bright red color. Incidentally, the term "Black Box" came from a meeting about the "Red Egg", when afterwards a journalist told Dr. Warren, "This is a wonderful black box." The unit itself was based on a wire recorder fitted into a perspex box firmly screwed together. The first commercial airliner fitted with an FDR was the Hawker-Siddeley HS121 Trident.
James "Crash" Ryan, from the University of Minnesota, developed the first aircraft "black box" flight recorder, patented in the U.S. in 1963. Ryan also developed a self-tensioning retractable seat belt mechanism, the first of its kind and now standard in all cars, also patented in 1963. His flight data recorder was a purely mechanical unit, which recorded flight data as impressions on metal film and was engineered to survive a crash, making it possible for the first time to objectively analyze the moments leading up to an accident. Today, the descendents of Ryan's black box are required equipment in all commercial and military aircraft, and are beginning to appear in commercial trucks and some consumer automobiles.
[edit] Design
The design of today's FDR is largely governed by the European Organisation for Civil Aviation Equipment[1] in its EUROCAE ED-112 (Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems). In the United States, the Federal Aviation Administration (FAA) regulates all aspects of U.S. aviation, and cites design requirements in their Technical Standard Order,[2] based on the European ED-112 (as do the aviation authorities of many other countries).
Currently, EUROCAE specifies that a recorder must be able to withstand an acceleration of 3400 g (33 km/s²) for 6.5 milliseconds. This is roughly equivalent to an impact velocity of 270 knots and a deceleration or crushing distance of 450 mm. Additionally, there are requirements for penetration resistance, static crush, high and low temperature fires, deep sea pressure, sea water immersion, and fluid immersion.
Modern day FDRs are typically plugged into the aircraft's fly-by-wire main data bus. They record significant flight parameters, including the control and actuator positions, engine information and time of day. There are 88 parameters required as a minimum under current U.S. federal regulations (only 29 were required until 2002), but some systems monitor many more variables. Generally each parameter is recorded a few times per second, though some units store "bursts" of data at a much faster frequency if the data begins to change quickly. Most FDRs record 25 hours worth of data in a continuous loop.
This has also given rise to flight data monitoring programs, whereby flights are analyzed for optimum fuel consumption and dangerous flight crew habits. The data from the FDR is transferred, in situ, to a solid state recording device and then periodically analyzed with some of the same technology used for accident investigations.
FDRs are usually located in the rear of the aircraft, typically in the tail. In this position, the entire front of the aircraft acts as a "crush zone" to reduce the shock that reaches the recorder. Also, modern FDRs are typically double wrapped, in strong corrosion-resistant stainless steel or titanium, with high-temperature insulation inside.
Since the recorders can sometimes be crushed into unreadable pieces, or even never located in deep water, some modern units are self-ejecting (taking advantage of kinetic energy at impact to separate themselves from the aircraft) and also equipped with radio and sonar beacons (see emergency locator transmitter) to aid in their location. Future regulations may require such recorders on civil aircraft.
[edit] See also
[edit] References
[edit] External links
[edit] General information
- U.S. Patent 3,075,192 — United States Patent Office link to James J. Ryan's Patent "Coding Aparatus for Flight Recorders and the Like"
- [1] — University of Minnesota article on the legacy of James "Crash" Ryan
- Black Box Flight Recorder — Australian Department of Defence article on the flight recorder
- Dave Warren - Inventor of the black box flight recorder — Australian Department of Defence article on the flight recorder's inventor
- How Black Boxes Work — Detailed seven page article from HowStuffWorks
- IRIG 106 Chapter 10 — Flight data recorder digital recorder standard
[edit] Dr David Warren (interview)
- ABC TV (Australia) Dr David Warren interview transcript 2003
- ABC TV (Australia) Dr David Warren interview transcript 2002
[edit] Manufacturers' websites
- Meggitt Avionics
- Hindustan Aeronautics Limited
- ETEP Airborne Recorders & Data acquisition systems
- DRS Technologies Inc. Deployable Flight Data Recorders
- Penny + Giles Aerospace Airborne Recorders
- Honeywell Flight Data Recorders
- L-3 Communications Corp. Aviation Recorders
- Smiths Aerospace Voice and Data Recorders
