Cockpit voice recorder
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A cockpit voice recorder (CVR), often referred to as a "black box", is a flight recorder used to record the audio environment in the flight deck of an aircraft for the purpose of investigation of accidents and incidents. This is typically achieved by recording the signals of the microphones and earphones of the pilots headsets and of an area microphone in the roof of the cockpit. The current applicable FAA TSO is C123b titled Cockpit Voice Recorder Equipment.
Where an aircraft is required to carry a CVR and utilises digital communications the CVR is required to record such communications with air traffic control unless this is recorded elsewhere. As of 2005[update] it is an FAA requirement that the recording duration is a minimum of thirty minutes, but the NTSB has long recommended that it should be at least two hours.
A standard CVR is capable of recording 4 channels of audio data for a period of 2 hours. The original requirement was for a CVR to record for 30 minutes, but this has been found to be insufficient in many cases, significant parts of the audio data needed for a subsequent investigation having occurred more than 30 minutes before the end of the recording.
The 1961 invention and patent for a "Cockpit Sound Recorder" by aeronautical engineer Edmund A. Boniface, Jr. is U.S. Patent 3,327,067. The Cockpit Sound Recorder (CSR) provided a progressive erasing/recording loop (lasting 30 or more minutes) of all sounds (explosion, voice, and the noise of any aircraft structural components undergoing serious fracture and breakage) which could be overheard in the cockpit and was an analog device as described by Boniface in his patent. Mr. Boniface's patent references U.S. Patent 2,426,838 by H.B. Miller for an "Endless Tape Magnetic Recording-Reproducing Device"; U.S. Patent 2,848,660 by J.S. Boyers for a "Mass Demagnetizing Device for Magnetic Recording Media"; and U.S. Patent 2,992,296 by Fritz Albrecht for a "Crash Data Recorder".
The earliest CVRs used analog wire recording, later replaced by analog magnetic tape. Some of the tape units used two reels, with the tape automatically reversing at each end. The original was the ARL Flight Memory Unit produced in 1957 by Australian David Warren and an instrument maker named Tych Mirfield.
Other units used a single reel, with the tape spliced into a continuous loop, much as in an 8-track cartridge. The tape would circulate and old audio information would be overwritten every 30 minutes. Recovery of sound from magnetic tape often proves difficult if the recorder is recovered from water and its housing has been breached. Thus, the latest designs employ solid-state memory and use digital recording techniques, making them much more resistant to shock, vibration and moisture. With the reduced power requirements of solid-state recorders, it is now practical to incorporate a battery in the units, so that recording can continue until flight termination, even if the aircraft electrical system fails.
Although it is commonly believed that flight data recorders and cockpit voice recorders are required on all US aircraft, in fact, they are only required on US aircraft that have 20 or more passenger seats or those that have six or more passenger seats, are turbo-charged, and require two pilots.
The CVR was developed in the 1950s chiefly in Australia. In the investigation of the 1960 crash of Trans Australia Airlines Flight 538 the inquiry judge strongly recommended that flight recorders be installed in all airliners. Australia became the first country in the world to make cockpit-voice recording compulsory. The United States first CVR rules were passed in 1964 requiring all turbine and piston aircraft with four or more engines to have CVRs by 1 March 1967.
Edmund A. Boniface, Jr. invented the COCKPIT SOUND RECORDER in 1961 while he was an aeronautical engineer with Lockheed California Company, a Division of Lockheed Aircraft Corporation; see U.S. Patent Number 3,327,067 dated June 20, 1967. His initial patent for an "Aircraft Cockpit Sound Recorder" (Serial No. 86,681 later abandoned) was filed with the U.S. Patent Office in February 1961 but was viewed by some as an "invasion of privacy". Subsequently in February 1963, Boniface filed a second time for the "Cockpit Sound Recorder" with the addition of a spring loaded switch that the pilot could use to erase the "Cockpit Sound Recorder" at the conclusion of a safe flight (see Patent Figure 2 Schematic of Invention Components). It was Mr. Boniface's participation in aircraft crash investigations in the 1940s and in the accident investigation of the loss of one of the wings at cruise altitude on each of two Lockheed Electra turboprop powered aircraft (Flight #542 operated by Braniff Airlines in 1959 and Flight #710 operated by Northwest Orient Airlines in 1960) that led to his wondering what the pilots may have said just prior to the wing loss and during the descent as well as the type and nature of any SOUNDS or explosions that may have preceded or occurred during the wing loss. U.S. Patent 3,327,067 by Edmund A. Boniface, Jr. required device for recording audio of pilot remarks and engine or other sounds to be "contained with the in-flight recorder within a sealed container that is shock mounted, fireproofed and made watertight" and "sealed in such a manner as to be capable of withstanding extreme temperatures during a crash fire". See lines 47 through 49 of U.S. Patent 3,327,067. [
The U.S. National Transportation Safety Board has asked for the installation of cockpit image recorders in large transport aircraft to provide information that would supplement existing CVR and FDR data in accident investigations. They also recommended image recorders be placed into smaller aircraft that are not required to have a CVR or FDR.
Such systems, estimated to cost less than $8,000 installed, typically consist of a camera and microphone located in the cockpit to continuously record cockpit instrumentation, the outside viewing area, engine sounds, radio communications, and ambient cockpit sounds. As with conventional CVRs and FDRs, data from such a system is stored in a crash-protected unit to ensure survivability.
Since the recorders can sometimes be crushed into unreadable pieces, or even 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 emergency locator transmitters and sonar underwater locator beacons to aid in their location.
On June 26, 2003, the Safe Aviation and Flight Enhancement Act was introduced and referred to the Committee on Transportation and Infrastructure of the U.S. House of Representatives. This bill would require installation of a second cockpit voice recorder, digital flight data recorder system and emergency locator transmitter that utilizes combination deployable recorder technology in each commercial passenger aircraft that is currently required to carry each of those recorders. The deployable recorder system would be ejected from the rear of the aircraft at the moment of an accident. The bill was referred to the House Subcommittee on Aviation during the 108th, 109th, and 110th congresses.
The Neue Deutsche Härte band Rammstein's album Reise, Reise is made to look like a CVR; it also includes a recording from a crash. The recording is from the last 1–2 minutes of the CVR of Japan Airlines Flight 123, which crashed on August 12, 1985, killing 520 people; JAL123 is the deadliest single-aircraft disaster in history.
Members of Collective: Unconscious made a theatrical presentation of a play called Charlie Victor Romeo with a script based on transcripts from CVR voice recordings of nine aircraft emergencies. The play features the famous United Airlines Flight 232 that landed in a cornfield near Sioux City, Iowa after suffering a catastrophic failure of one engine and most flight controls.
Survivor, a novel by Chuck Palahniuk, is about a cult member who dictates his life story to a flight recorder before the plane runs out of fuel and crashes.
- Acronyms and abbreviations in avionics
- Air safety
- Black box (transportation)
- Distress radiobeacon, (EPIRB), (ELT)
- Flight data recorder
- List of unrecovered flight recorders
- "France to resume 'black box' hunt". BBC News. 2009-12-13. Retrieved 2010-04-30.
- "Cockpit Voice Recorder Equipment" (PDF). Federal Aviation Administration. 2006-06-01. Retrieved 2007-04-21.
- "Federal Aviation Regulation Sec. 121.359 - Cockpit voice recorders". Risingup.com. Retrieved 2013-02-07.
- "2011 Most Wanted List Page. Recorders." NTSB
- "Federal Aviation Regulation Sec. 23.1457 - Cockpit voice recorders". Risingup.com. Retrieved 2013-02-07.
- "Dave Warren - Inventor of the black box flight recorder ", DSTO-dsto.defence.gov.au, 29 March 2005, Retrieved 20 April 2010
- Neil Campbell, The Evolution of Flight Data Analysis, Proc. Australian Society of Air Safety Investigators conference, 2007, visible here
- Nick Komos (August 1989). Air Progress: 76.
- 108th Congress House Resolution 2632 THOMAS (Library of Congress)
- 109th Congress House Resolution 3336 THOMAS (Library of Congress)
- 110th Congress House Resolution 4336 THOMAS (Library of Congress)
- "Data Collection and Improved Technologies" NTSB
- "Collective: Unconscious". Charlievictorromeo.com. 2012-07-03. Retrieved 2013-02-07.
Cockpit Sound Recorder invented and patented by Edmund A. Boniface, Jr. in 1963 and is U.S. Patent 3,327,067
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