Cockpit voice recorder
Encyclopedia
Flight recorder
A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of an aircraft accident or incident. For this reason, flight recorders are required to be capable of surviving the conditions likely to be encountered in a severe aircraft...
used to record the audio environment in the flight deck
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
of an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
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
Technical Standard Order
A Technical Standard Order is a minimum performance standard issued by the United States Federal Aviation Administration for specified materials, parts, processes, and appliances used on civil aircraft. Articles with TSO design approval are eligible for use on the United States type certificated...
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. 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.
Overview
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 earliest CVRs used analog wire recording
Wire recording
Wire recording is a type of analog audio storage in which a magnetic recording is made on thin steel or stainless steel wire.The wire is pulled rapidly across a recording head which magnetizes each point along the wire in accordance with the intensity and polarity of the electrical audio signal...
, later replaced by analog magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
. Some of the tape units used two reels, with the tape automatically reversing at each end. The original was the ARL Flight Memory Unit
Flight data recorder
A flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
produced in 1957 by Australian David Warren
David Warren (inventor)
David Ronald de Mey Warren AO was an Australian scientist, best known for inventing and developing the flight data recorder and cockpit voice recorder .-Early life:...
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
8-track cartridge
Stereo 8, commonly known as the eight-track cartridge, eight-track tape, or simply eight-track, is a magnetic tape sound recording technology. It was popular in the United States from the mid-1960s through the late 1970s, but was relatively unknown in many European countries...
. 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.
Like the flight data recorder
Flight data recorder
A flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
(FDR), the CVR is typically mounted in the tail section (the empennage) of an airplane to maximize the likelihood of its survival in a crash.
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.
History
The CVR was developed in the 1950s chiefly in Australia. In 1960, following an aircraft crash in QueenslandQueensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, 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.
Future devices
The U.S. National Transportation Safety BoardNational Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
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
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
at impact to separate themselves from the aircraft) and also equipped with radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
emergency locator transmitters and sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
underwater locator beacon
Underwater locator beacon
An underwater locator beacon or underwater acoustic beacon is a device fitted to aviation flight recorders such as the cockpit voice recorder and flight data recorder. ULBs are also sometimes required to be attached directly to an aircraft fuselage...
s to aid in their location.
On 19 July 2005, the Safe Aviation and Flight Enhancement Act of 2005 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
Digital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
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.
Related
The U.S. National Transportation Safety BoardNational Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
has recommended that railroad voice recorders be required in locomotive
Locomotive
A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...
s.
Cultural references
The Neue Deutsche HärteNeue Deutsche Härte
Neue Deutsche Härte is a genre of industrial metal. The term was invented by the German music press after the release of the debut album Herzeleid by Rammstein....
band Rammstein
Rammstein
Rammstein is a German Neue Deutsche Härte band from Berlin, formed in 1994. The band consists of members Till Lindemann , Richard Z. Kruspe , Paul H. Landers , Oliver "Ollie" Riedel , Christoph "Doom" Schneider and Christian "Flake" Lorenz...
's album Reise, Reise
Reise, Reise
Reise, Reise is Neue Deutsche Härte band Rammstein's fourth studio album. It was released on 27 September 2004 in Germany and followed shortly by its release across Europe. It was released in North America on 16 November 2004...
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
Japan Airlines Flight 123
Japan Airlines Flight 123 was a Japan Airlines domestic flight from Tokyo International Airport to Osaka International Airport on August 12, 1985. The Boeing 747-146SR that made this route, registered , suffered mechanical failures 12 minutes into the flight and 32 minutes later crashed into two...
, which crashed on August 12, 1985, killing 520 people; JAL123 is the deadliest single-aircraft disaster in history.
Members of Collective: Unconscious
Collective: Unconscious
Collective:Unconscious is a non-profit corporation, founded in New York City in 1994, and incorporated in 1995. Originally based on Ludlow Street on New York's Lower East Side, in 2004 it relocated to Tribeca until July 2008....
made a theatrical presentation of a play called Charlie Victor Romeo
Charlie Victor Romeo
Charlie Victor Romeo is a 1999 play whose script consists of almost-verbatim transcripts from six real-life aviation accidents and incidents. "Charlie Victor Romeo," or CVR, derived from the NATO phonetic alphabet, is aviation lingo for cockpit voice recorder...
with a script based on transcripts from CVR voice recordings of nine aircraft emergencies. The play features the famous United Airlines Flight 232
United Airlines Flight 232
United Airlines Flight 232 was a scheduled flight from Stapleton International Airport in Denver, Colorado, to O'Hare International Airport in Chicago, with continuing service to Philadelphia International Airport...
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.
See also
- Acronyms and abbreviations in avionicsAcronyms and abbreviations in avionics-A:*ACARS: Aircraft Communications Addressing and Reporting System.*ACAS: Airborne Collision Avoidance System.*ACP: Audio Control Panel.*ACS: Audio Control System.*ADAHRS: Air Data and Attitude Heading Reference System.*ADC: Air Data Computer....
- Air safetyAir safetyAir safety is a term encompassing the theory, investigation and categorization of flight failures, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.-United...
- Black box (transportation)Black Box (transportation)The term black box is a placeholder name used casually to refer to a collection of several different recording devices used in transportation: the flight recorders in aircraft, the event recorder in railway locomotives, the event data recorder in automobiles, message case in ships, and other...
- Distress radiobeacon, (EPIRB), (ELT)
- Flight data recorderFlight data recorderA flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
- List of unrecovered flight recorders
External links
- 'The ARL ‘Black Box’ Flight Recorder' — Melbourne University history honours thesis on the development of the first cockpit voice recorder by David WarrenDavid Warren (inventor)David Ronald de Mey Warren AO was an Australian scientist, best known for inventing and developing the flight data recorder and cockpit voice recorder .-Early life:...