
A flight recorder is an electronic recording device placed in an
aircraft
An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...
for the purpose of facilitating the investigation of
aviation accidents and incidents
An aviation accident is an event during aircraft operation that results serious injury, death, or significant destruction. An aviation incident is any operating event that compromises safety but does not escalate into an aviation accident. Pre ...
. The device may often be referred to colloquially as a "black box", an outdated name which has become a
misnomer
A misnomer is a name that is incorrectly or unsuitably applied. Misnomers often arise because something was named long before its correct nature was known, or because an earlier form of something has been replaced by a later form to which the nam ...
—they are now required to be painted
bright orange, to aid in their recovery after accidents.
There are two types of flight recording devices: the flight data recorder (FDR) preserves the recent history of the flight through the recording of dozens of parameters collected several times per second; the cockpit voice recorder (CVR) preserves the recent history of the sounds in the cockpit, including the conversation of the pilots. The two devices may be combined into a single unit. Together, the FDR and CVR objectively document the aircraft's flight history, which may assist in any later investigation.
The two flight recorders are required by international regulation, overseen by the
International Civil Aviation Organization
The International Civil Aviation Organization (ICAO ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international sch ...
, to be capable of surviving the conditions likely to be encountered in a severe aircraft accident. For this reason, they are typically specified to withstand an impact of 3400
''g'' and temperatures of over , as required by
EUROCAE ED-112. They have been a mandatory requirement in commercial aircraft in the United States since 1967. After the unexplained disappearance of
Malaysia Airlines Flight 370
Malaysia Airlines Flight 370 (MH370/MAS370) was an international passenger flight operated by Malaysia Airlines that disappeared from radar on 8 March 2014, while flying from Kuala Lumpur International Airport in Malaysia to its planned de ...
in 2014, commentators have called for live streaming of data to the ground, as well as extending the battery life of the underwater locator beacons.
History
In seafaring, a device which recorded the position of different vessels in case of an accident was patented by John Sen Inches Thomson in January, 1897.
Early designs
One of the earliest and proven attempts was made by
François Hussenot and Paul Beaudouin in 1939 at the
Marignane
Marignane (; ) is a commune in the Bouches-du-Rhône department in the Provence-Alpes-Côte d'Azur region in southern France.
Geography
It is a component of the Aix-Marseille-Provence Metropolis, and the largest suburb of the city of Marsei ...
flight test center, France, with their "type HB" flight recorder; they were essentially photograph-based flight recorders, because the record was made on a scrolling
photographic film
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the ...
long by wide. The
latent image
A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of ...
was made by a thin ray of light deviated by a mirror tilted according to the magnitude of the data to be recorded (altitude, speed, etc.).
A pre-production run of 25 "HB" recorders was ordered in 1941 and HB recorders remained in use in French flight test centers well into the 1970s.
In 1947, Hussenot founded the Société Française des Instruments de Mesure with Beaudouin and another associate, so as to market his invention, which was also known as the "hussenograph". This company went on to become a major supplier of data recorders, used not only aboard aircraft but also trains and other vehicles. SFIM is today part of the
Safran
Safran S.A. () is a French Multinational corporation, multinational aerospace, defence industry, defence and computer security, security corporation headquartered in Paris. It designs, develops and manufactures both commercial and military airc ...
group and is still present in the flight recorder market. The advantage of the film technology was that it could be easily developed afterwards and provides a durable, visual feedback of the flight parameters without needing any playback device. On the other hand, unlike magnetic tapes or later flash memory-based technology, a photographic film cannot be erased and reused, and so must be changed periodically. The technology was reserved for one-shot uses, mostly during planned test flights: it was not mounted aboard civilian aircraft during routine commercial flights. Also, cockpit conversation was not recorded.
Another form of flight data recorder was developed in the UK during World War II. Len Harrison and Vic Husband developed a unit that could withstand a crash and fire to keep the flight data intact. The unit was the forerunner of today's recorders, in being able to withstand conditions that aircrew could not. It used copper foil as the recording medium, with various styli, corresponding to various instruments or aircraft controls, indenting the foil. The foil was periodically advanced at set time intervals, giving a history of the aircraft's instrument readings and control settings. The unit was developed at
Farnborough for the
Ministry of Aircraft Production. At the war's end the Ministry got Harrison and Husband to sign over their invention to it and the Ministry patented it under British patent 19330/45.
The first modern flight data recorder, called "Mata-Hari", named after the famous
spy, was created in 1942 by Finnish aviation engineer Veijo Hietala. This black high-tech mechanical box was able to record all required data during test flights of
fighter aircraft
Fighter aircraft (early on also ''pursuit aircraft'') are military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air supremacy, air superiority of the battlespace. Domina ...
that the
Finnish Air Force
The Finnish Air Force (FAF or FiAF; ; ) is one of the branches of the Finnish Defence Forces. Its peacetime tasks are airspace surveillance, identification flights, and production of readiness formations for wartime conditions. The Finnish Air ...
repaired or built in its main
aviation factory in
Tampere
Tampere is a city in Finland and the regional capital of Pirkanmaa. It is located in the Finnish Lakeland. The population of Tampere is approximately , while the metropolitan area has a population of approximately . It is the most populous mu ...
, Finland.
During World War II both British and American air forces successfully experimented with aircraft voice recorders. In August 1943 the
USAAF
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
conducted an experiment with a
magnetic wire recorder to capture the inter-phone conversations of a B-17 bomber flight crew on a combat mission over Nazi-occupied France. The recording was broadcast back to the United States by radio two days afterwards.
Australian designs
In 1953, while working at the Aeronautical Research Laboratories (ARL) of the
Defence Science and Technology Organisation
Defense or defence may refer to:
Tactical, martial, and political acts or groups
* Defense (military), forces primarily intended for warfare
* Civil defense, the organizing of civilians to deal with emergencies or enemy attacks
* Defense indust ...
in
Melbourne
Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...
,
Australian research scientist
David Warren conceived a device that would record not only the instrument readings, but also the voices in the cockpit.
In 1954 he published a report entitled "A Device for Assisting Investigation into Aircraft Accidents".
Warren built a
prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototype ...
FDR called "The ARL Flight Memory Unit" in 1956,
and in 1958 he built the first combined FDR/CVR prototype.
It was designed with civilian aircraft in mind, explicitly for post-crash examination purposes.
Aviation authorities from around the world were largely uninterested at first, but this changed in 1958 when Sir Robert Hardingham, the
secretary
A secretary, administrative assistant, executive assistant, personal secretary, or other similar titles is an individual whose work consists of supporting management, including executives, using a variety of project management, program evalu ...
of the
British Air Registration Board, visited the ARL and was introduced to David Warren.
Hardingham realized the significance of the invention and arranged for Warren to demonstrate the prototype in the UK.
The ARL assigned an engineering team to help Warren develop the prototype to the airborne stage. The team, consisting of electronics engineers Lane Sear, Wally Boswell, and Ken Fraser, developed a working design that incorporated a fire-resistant and shockproof case, a reliable system for encoding and recording aircraft instrument readings and voice on one wire, and a ground-based decoding device. The ARL system, made by the British firm of S. Davall & Sons Ltd, in
Middlesex
Middlesex (; abbreviation: Middx) is a Historic counties of England, former county in South East England, now mainly within Greater London. Its boundaries largely followed three rivers: the River Thames, Thames in the south, the River Lea, Le ...
, was named the "Red Egg" because of its shape and bright red color.
The units were redesigned in 1965 and relocated at the rear of aircraft to increase the probability of successful data retrieval after a crash.
Carriage of data recording equipment became mandatory in UK-registered aircraft in two phases; the first, for new turbine-engined public transport category aircraft over in weight, was mandated in 1965, with a further requirement in 1966 for piston-engined transports over , with the earlier requirement further extended to all jet transports. One of the first UK uses of the data recovered from an aircraft accident was that recovered from the Royston "Midas" data recorder that was on board the
British Midland Argonaut involved in the
Stockport Air Disaster in 1967.
American designs
A flight recorder was invented and patented in the United States by James J. Ryan. Ryan's "Flight Recorder" patent was filed in August 1953 and approved on November 8, 1960, as US Patent 2,959,459. A second patent by Ryan for a "Coding Apparatus For Flight Recorders" is US Patent 3,075,192 dated January 22, 1963.
A "Cockpit Sound Recorder" (CSR) was independently invented and patented by Edmund A. Boniface Jr., an aeronautical engineer at
Lockheed Aircraft Corporation.
He originally filed with the US Patent Office on February 2, 1961, as an "Aircraft Cockpit Sound Recorder". The 1961 invention was viewed by some as an "invasion of privacy". Subsequently, Boniface filed again on February 4, 1963, for a "Cockpit Sound Recorder" (US Patent 3,327,067)
with the addition of a spring-loaded switch which allowed the pilot to erase the audio/sound tape recording at the conclusion of a safe flight and landing.
Boniface's participation in aircraft crash investigations in the 1940s and in the accident investigations 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 1961) 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.
[US Patent 3,327,067 for Cockpit Sound Recorder by Edmund A. Boniface, Jr.](_blank)
;
His patent was for a 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". The CSR was an analog device which provided a continuous 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.
On November 1, 1966, the director of the Bureau of Safety of the Civil Aeronautics Board Bobbie R. Allen and the chief of Technical Services Section John S. Leak presented "The Potential Role of Flight Recorders in Aircraft Accident Investigation" at the AIAA/CASI Joint Meeting on Aviation Safety,
Toronto
Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...
, Canada.
Terminology

The term "black box" was a World War II British phrase, originating with the development of radio, radar, and electronic navigational aids in British and Allied combat aircraft. These often-secret electronic devices were encased in non-reflective black boxes or housings. The earliest identified reference to "black boxes" occurs in a May 1945 ''
Flight
Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...
'' article, "Radar for Airlines", describing the application of wartime RAF radar and navigational aids to civilian aircraft: "The stowage of the 'black boxes' and, even more important, the detrimental effect on performance of external aerials, still remain as a radio and radar problem." (The term "
black box
In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The te ...
" is used with a different meaning in science and engineering, describing a system exclusively by its inputs and outputs, with no information whatsoever about its inner workings.)
Magnetic tape and wire voice recorders had been tested on
RAF and
USAAF
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
bombers by 1943 thus adding to the assemblage of fielded and experimental electronic devices employed on Allied aircraft. As early as 1944 aviation writers envisioned use of these recording devices on commercial aircraft to aid incident investigations. When modern flight recorders were proposed to the British
Aeronautical Research Council in 1958, the term "black box" was in colloquial use by experts.
By 1967, when flight recorders were mandated by leading aviation countries, the expression had found its way into general use: "These so-called 'black boxes' are, in fact, of fluorescent flame-orange in colour." The formal names of the devices are ''flight data recorder'' and ''cockpit voice recorder''. The recorders must be housed in boxes that are bright orange in color to make them more visually conspicuous in the debris after an accident.
Components
Flight data recorder

A flight data recorder (FDR; also ADR, for ''accident data recorder'') is an electronic device employed to record instructions sent to any electronic systems on an aircraft.
The data recorded by the FDR are used for
accident and incident investigation. Due to their importance in investigating accidents, these
ICAO
The International Civil Aviation Organization (ICAO ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international sch ...
-regulated devices are carefully engineered and constructed to withstand the force of a high speed impact and the heat of an intense fire. Contrary to the popular term "black box", the exterior of the FDR is coated with heat-resistant
bright orange paint for high visibility in wreckage, and the unit is usually mounted in the aircraft's
tail section, where it is more likely to survive a crash. Following an accident, the recovery of the FDR is usually a high priority for the investigating body, as analysis of the recorded parameters can often detect and identify causes or contributing factors.
Modern day FDRs receive inputs via specific data frames from the
flight-data acquisition units. They record significant
flight
Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...
parameters, including the control and
actuator
An actuator is a machine element, component of a machine that produces force, torque, or Displacement (geometry), displacement, when an electrical, Pneumatics, pneumatic or Hydraulic fluid, hydraulic input is supplied to it in a system (called an ...
positions, engine information and
time of day. There are 88 parameters required as a minimum under current US 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
The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of U ...
, though some units store "bursts" of data at a much higher
frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...
if the data begin to change quickly. Most FDRs record approximately 17–25 hours of data in a continuous loop. It is required by regulations that an FDR verification check (readout) is performed annually in order to verify that all mandatory parameters are recorded. Many aircraft today are equipped with an "event" button in the cockpit that could be activated by the crew if an abnormality occurs in flight. Pushing the button places a signal on the recording, marking the time of the event.
Modern FDRs are typically double wrapped in strong
corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
-resistant
stainless steel
Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...
or
titanium
Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...
, with high-temperature
insulation inside. Modern FDRs are accompanied by an
underwater locator beacon that emits an ultrasonic "ping" to aid in detection when submerged. These beacons operate for up to 30 days and are able to operate while immersed to a depth of up to .
Cockpit voice recorder

A cockpit voice recorder (CVR) is a flight recorder used to record the audio environment in the
flight deck
The flight deck of an aircraft carrier is the surface on which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters ...
of an
aircraft
An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...
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 uses 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 two hours.
The
European Aviation Safety Agency
The European Union Aviation Safety Agency (EASA) is an agency of the European Commission with responsibility for civil aviation safety in the European Union. It carries out certification, regulation and standardisation and also performs inve ...
increased the recording duration to 25 hours in 2021. In 2023, the FAA proposed extending requirements to 25 hours to help in investigations like runway incursions. In a January 2024 press conference on
Alaska Airlines Flight 1282,
National Transportation Safety Board
The National Transportation Safety Board (NTSB) 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 inci ...
(NTSB) chair
Jennifer Homendy again called for extending retention to 25 hours, rather than the currently-mandated 2 hours, on all existing devices, rather than only newly manufactured ones.
A standard CVR is capable of recording four channels of audio data for a period of two hours. The original requirement was for a CVR to record for 30 minutes, but this has been found to be insufficient in many cases because significant parts of the audio data needed for a subsequent investigation occurred more than 30 minutes before the end of the recording.
The earliest CVRs used analog
wire recording
Wire recording, also known as magnetic wire recording, was the first magnetic recording technology, an analog type of audio storage. It recorded sound signals on a thin steel wire using varying levels of magnetization. The first crude magne ...
, later replaced by analog
magnetic tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic ...
. 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
Australian(s) may refer to:
Australia
* Australia, a country
* Australians, citizens of the Commonwealth of Australia
** European Australians
** Anglo-Celtic Australians, Australians descended principally from British colonists
** Aboriginal Aus ...
David Warren and instrument maker
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 fault tolerant
digital recording
In digital recording, an audio signal, audio or video signal is converted into a stream of discrete numbers representing the changes over time in air pressure for audio, or Color, chroma and luminance values for video. This number stream is s ...
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 FDR, the CVR is typically mounted in the rear of the airplane
fuselage
The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...
to maximize the likelihood of its survival in a crash.
Combined units
With the advent of digital recorders, the FDR and CVR can be manufactured in one fireproof, shock proof, and waterproof container as a combined digital cockpit voice and data recorder (CVDR). Currently, CVDRs are manufactured by
L3Harris Technologies
L3Harris Technologies, Inc. is an American technology company, defense contractor, and information technology service (economics), services provider that produces products for command and control systems, wireless equipment, tactical radios, avi ...
and
Hensoldt
Hensoldt AG ''(HENSOLDT)'' is a multinational corporation headquartered in Germany which focuses on sensor technologies for protection and surveillance missions in the Military, defence, security and aerospace sectors. The main product areas are r ...
among others. The Enhanced Airborne Flight Recorder (EAFR), manufactured by
General Electric
General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston.
Over the year ...
and fitted to the Boeing 787, is a combined recorder which also includes a Recorder Independent Power Supply (RIPS) to allow continued operation in the event of a power failure.
Solid state recorders became commercially practical in 1990, having the advantage of not requiring scheduled maintenance and making the data easier to retrieve. This was extended to the two-hour voice recording in 1995.
Additional equipment
Since the 1970s, most large civil jet transports have been additionally equipped with a "
quick access recorder" (QAR). This records data on a removable storage medium. Access to the FDR and CVR is necessarily difficult because they must be fitted where they are most likely to survive an accident; they also require specialized equipment to read the recording. The QAR recording medium is readily removable and is designed to be read by equipment attached to a standard desktop computer. In many airlines, the quick access recordings are scanned for "events", an event being a significant deviation from normal operational parameters. This allows operational problems to be detected and eliminated before an accident or incident results.
A flight-data acquisition unit (FDAU) is a unit that receives various discrete, analog and digital parameters from a number of sensors and
avionic systems and then routes them to the FDR and, if installed, to the QAR. Information from the FDAU to the FDR is sent via specific data frames, which depend on the aircraft manufacturer.
Many modern aircraft systems are
digital or digitally controlled. Very often, the digital system will include
built-in test equipment
Built-in test equipment (BITE) for avionics primarily refers to passive fault management and diagnosis equipment built into airborne systems to support maintenance processes. Built-in test equipment includes multimeter
A multimeter (also know ...
which records information about the operation of the system. This information may also be accessed to assist with the investigation of an accident or incident.
Specifications

The design of today's FDR is governed by the internationally recognized standards and recommended practices relating to flight recorders which are contained in
ICAO
The International Civil Aviation Organization (ICAO ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international sch ...
Annex 6 which makes reference to industry
crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Different criteria are used to figure out how safe a structure is in a crash, ...
and
fire protection
Fire protection is the study and practice of mitigating the unwanted effects of potentially Conflagration, destructive fires. It involves the study of the behaviour, Compartmentalization (fire protection), compartmentalisation, suppression and inve ...
specifications such as those to be found in the European Organisation for Civil Aviation Equipment
documents EUROCAE ED55, ED56 Fiken A and ED112 (Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems). In the United States, the
Federal Aviation Administration
The Federal Aviation Administration (FAA) is a Federal government of the United States, U.S. federal government agency within the United States Department of Transportation, U.S. Department of Transportation that regulates civil aviation in t ...
(FAA) regulates all aspects of US aviation, and cites
design
A design is the concept or proposal for an object, process, or system. The word ''design'' refers to something that is or has been intentionally created by a thinking agent, and is sometimes used to refer to the inherent nature of something ...
requirement
In engineering, a requirement is a condition that must be satisfied for the output of a work effort to be acceptable. It is an explicit, objective, clear and often quantitative description of a condition to be satisfied by a material, design, pro ...
s in their Technical Standard Order,
based on the EUROCAE documents (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/s
2) for 6.5
millisecond
A millisecond (from '' milli-'' and second; symbol: ms) is a unit of time in the International System of Units equal to one thousandth (0.001 or 10−3 or 1/1000) of a second or 1000 microseconds.
A millisecond is to one second, as one second i ...
s. This is roughly equivalent to an
impact
Impact may refer to:
* Impact (mechanics), a large force or mechanical shock over a short period of time
* Impact, Texas, a town in Taylor County, Texas, US
Science and technology
* Impact crater, a meteor crater caused by an impact event
* Imp ...
velocity
Velocity is a measurement of speed in a certain direction of motion. It is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of physical objects. Velocity is a vector (geometry), vector Physical q ...
of and a
deceleration
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Acceleration is one of several components of kinematics, the study of motion. Accelerations are vector quantities (in that they have magnit ...
or crushing distance of . Additionally, there are
requirement
In engineering, a requirement is a condition that must be satisfied for the output of a work effort to be acceptable. It is an explicit, objective, clear and often quantitative description of a condition to be satisfied by a material, design, pro ...
s for penetration resistance,
static crush, high and low temperature
fire
Fire is the rapid oxidation of a fuel in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products.
Flames, the most visible portion of the fire, are produced in the combustion re ...
s, deep sea
pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...
,
sea water
Seawater, or sea water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximate ...
immersion, and
fluid
In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...
immersion.
EUROCAE ED-112 (Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems) defines the minimum specification to be met for all aircraft requiring flight recorders for recording of flight data, cockpit audio, images and CNS / ATM digital messages and used for investigations of accidents or incidents.
When issued in March 2003, ED-112 superseded previous ED-55 and ED-56A that were separate specifications for FDR and CVR.
FAA TSOs for FDR and CVR reference ED-112 for characteristics common to both types.
In order to facilitate recovery of the recorder from an aircraft accident site, they are required to be coloured bright yellow or orange with reflective surfaces. All are lettered "Flight recorder do not open" on one side in English and "''Enregistreur de vol ne pas ouvrir''" in French on the other side. To assist recovery from submerged sites they must be equipped with an underwater locator beacon which is automatically activated in the event of an accident.
Regulation
The first regulatory attempt to require flight data recorders occurred in April 1941, when the
Civil Aeronautics Board
The Civil Aeronautics Board (CAB) was an agency of the federal government of the United States, formed in 1940 from a split of the Civil Aeronautics Authority and abolished in 1985, that regulated aviation services (including scheduled passe ...
(CAB) required flight recorders on passenger aircraft that would record the aircraft's altitude and whether the radio transmitter was turned on or off.
The compliance deadline for that regulation was extended several times, until June 1944 when the requirement was rescinded due to maintenance problems and the lack of parts due to World War 2.
A similar regulation was adopted in September 1947, which required recorders in aircraft of or more, but that requirement was again rescinded in July 1948 because of a lack of availability of reliable devices.
In August 1957, the CAB adopted amendments to flight regulations that required the installation of flight recorders by July 1958 in all aircraft over and that were operated at altitudes over 25,000 feet.
The requirements were further amended in September 1959, requiring the retention of records for 60 days, and the operation of the flight recorders continuously from the time of takeoff roll to the completion of the landing roll.
In the investigation of the 1960 crash of
Trans Australia Airlines Flight 538 at Mackay,
Queensland
Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...
, the inquiry judge strongly recommended that flight recorders be installed in all Australian airliners. Australia became the first country in the world to make cockpit-voice recording compulsory.

The United States' first cockpit voice recorder rules were passed in 1964, requiring all turbine and piston aircraft with four or more engines to have CVRs by March 1, 1967.
it is an FAA requirement that the CVR recording duration is a minimum of two hours,
following the NTSB recommendation that it should be increased from its previously mandated 30-minute duration.
From 2014 the United States requires flight data recorders and cockpit voice recorders on aircraft that have 20 or more passenger seats, or those that have six or more passenger seats, are turbine-powered, and require two pilots.
For US air carriers and manufacturers, the NTSB is responsible for investigating accidents and safety-related incidents. The NTSB also serves in an advisory role for many international investigations not under its formal jurisdiction. The NTSB does not have regulatory authority, but must depend on legislation and other government agencies to act on its safety recommendations.
In addition, after the public outcry that followed recordings released for the crash of
Delta Air Lines Flight 1141 in 1988, 49 USC Section 1114(c) prohibits the NTSB from making the audio recordings public except when related to a safety investigation, and in such cases the release is only in the form of a written transcript.
The
ARINC Standards are prepared by the Airlines Electronic Engineering Committee (AEEC). The 700 Series of standards describe the form, fit, and function of avionics equipment installed predominately on transport category aircraft. The FDR is defined by ARINC Characteristic 747. The CVR is defined by ARINC Characteristic 757.
Post-incident overwriting of voice data by Nigerian crews led to a 2023 All Operators Letter reinforcing that this practice is forbidden.
Proposed requirements
Deployable recorders
The NTSB recommended in 1999 that operators be required to install two sets of CVDR systems, with the second CVDR designed to be ejected from the aircraft prior to impact with the ground or water. Ejection would be initiated by computer based on sensor information indicating an accident is imminent. A deployable recorder combines the cockpit voice/flight data recorders and an emergency locator transmitter (ELT) in a single unit. The unit would be designed to eject and float away from the aircraft and survive its descent to the ground, or float on water indefinitely. It would be equipped with satellite technology to aid in prompt recovery. Deployable CVDR technology has been used by the US Navy since 1993.
While the recommendations would involve a massive, expensive retrofit program, government funding would meet cost objections from manufacturers and airlines. Operators would get both sets of recorders (including the currently-used fixed recorder) free of charge. The cost of the second deployable/ejectable CVDR (or black box) was estimated at US$30 million for installation in 500 new aircraft (about $60,000 per new commercial plane).
In the United States, the proposed SAFE Act calls for implementing the NTSB 1999 recommendations. However, so far the proposed legislation has failed to pass
Congress
A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...
, having been introduced in 2003 (H.R. 2632), in 2005 (H.R. 3336), and in 2007 (H.R. 4336).
Originally the Safe Aviation Flight Enhancement (SAFE) Act of 2003 was introduced on June 26, 2003, by Congressman
David Price (D-NC) and Congressman
John Duncan (R-Tenn.) in a bipartisan effort to ensure investigators have access to information immediately following accidents to
transport category aircraft.
On July 19, 2005, a revised proposal for a SAFE Act was introduced and referred to the Committee on Transportation and Infrastructure of the US House of Representatives. The bill was referred to the House Subcommittee on Aviation during the 108th, 109th, and 110th Congresses.
After Malaysia Airlines Flight 370
In the United States, on March 12, 2014, in response to the missing
Malaysia Airlines Flight 370
Malaysia Airlines Flight 370 (MH370/MAS370) was an international passenger flight operated by Malaysia Airlines that disappeared from radar on 8 March 2014, while flying from Kuala Lumpur International Airport in Malaysia to its planned de ...
,
David Price re-introduced the SAFE Act in the US House of Representatives.
The disappearance of Malaysia Airlines Flight 370 demonstrated the limits of the contemporary flight recorder technology, namely how physical possession of the flight recorder device is necessary to help investigate the cause of an aircraft incident. Considering the advances of modern communication, technology commentators called for flight recorders to be supplemented or replaced by a system that provides "live streaming" of data from the aircraft to the ground.
Furthermore, commentators called for the underwater locator beacon's range and battery life to be extended, as well as the outfitting of civil aircraft with the deployable flight recorders typically used in military aircraft. Previous to MH370, the investigators of 2009
Air France Flight 447
Air France Flight 447 was a scheduled international passenger flight from Rio de Janeiro/Galeão International Airport, Rio de Janeiro, Brazil, to Charles de Gaulle Airport, Paris, France. On 1 June 2009, inconsistent airspeed indications and mi ...
urged that the battery life be extended as "rapidly as possible" after the crash's flight recorders went unrecovered for over a year.
After Indonesia AirAsia Flight 8501
On December 28, 2014,
Indonesia AirAsia Flight 8501, en route from
Surabaya
Surabaya is the capital city of East Java Provinces of Indonesia, province and the List of Indonesian cities by population, second-largest city in Indonesia, after Jakarta. Located on the northeastern corner of Java island, on the Madura Strai ...
, Indonesia, to
Singapore
Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...
, crashed in bad weather, killing all 155 passengers and seven crew on board.
On January 8, 2015, before the recovery of the flight recorders, an anonymous
ICAO
The International Civil Aviation Organization (ICAO ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international sch ...
representative said: "The time has come that deployable recorders are going to get a serious look."
A second ICAO official said that public attention had "galvanized momentum in favour of ejectable recorders on commercial aircraft".
Boeing 737 MAX
Live flight data streaming as on the ecoDemonstrator#2018: Boeing 777F, Boeing 777F ecoDemonstrator, plus 20 minutes of data before and after a triggering event, could have removed the uncertainty before the Boeing 737 MAX groundings following the March 2019 Ethiopian Airlines Flight 302 crash. In the
Alaska Airlines Flight 1282 accident, the Cockpit Voice Recorder functioned properly but the data was overwritten as the CVR remained powered, and functioning. The critical accident data was overwritten by over two hours of post-incident sounds until a maintenance crew could enter the aircraft after the incident and power down the CVR.
Image recorders
The NTSB 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 have recommended that image recorders be placed into smaller aircraft that are not required to have a CVR or FDR.
The rationale is that what is seen on an instrument by the pilots of an aircraft is not necessarily the same as the data sent to the display device. This is particularly true of aircraft equipped with electronic displays (Cathode-ray tube, CRT or LCD). A mechanical instrument panel is likely to preserve its last indications, but this is not the case with an electronic display. 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.
Cultural references
* The artwork for the 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 Air Lines Flight 123, which crashed on August 12, 1985, killing 520 people; JAL123 is the deadliest single-aircraft disaster in history.
* Members of the performing arts collective 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 crash-landed in a cornfield near Sioux City, Iowa, after suffering a catastrophic failure of one engine and most flight controls.
* ''Survivor (Palahniuk novel), Survivor'', a novel by American author 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.
* In stand-up comedy, many jokes have been made asking why the entire airplane is not made out of the material used to make black boxes, given that the black box survives the crash. This is referenced in the 2001 Chris Rock movie ''Down to Earth (2001 film), Down to Earth'', although the original joke is widely credited to George Carlin.
See also
* Acronyms and abbreviations in avionics
* Data logger
* Emergency locator beacon
* Emergency position-indicating radiobeacon station
* Event data recorder
* Flight operations quality assurance
* Korean Air Lines Flight 007
* List of unrecovered and unusable flight recorders
* Quick access recorder
* Record and replay debugging, Software flight recorder
* Train event recorder
* Voyage data recorder
References
Further reading
* American Aviation Historical Society, Volume 59, Fall-Winter 2014
"Edmund A. Boniface, Jr.: Inventing the Cockpit Sound Recorder"
"Extraordinary Inventor" ''U of A Engineer Magazine'', Winter 2005
* (''Survivors'')
NRC, 2008-03-05
* Jeremy Sear
University of Melbourne, October 2001
*
*
*
External links
Melbourne University history honors thesis on the development of the first cockpit voice recorder by David Warren
Finnish Mata-Hari Flight Recorder in Museums of Tampere City"Beyond the Black Box: Instead of storing flight data on board, aircraft could easily send the information in real time to the ground" by Krishna M. Kavi, ''IEEE Spectrum'', August 2010
*
ABC TV (Australia)
ABC TV (Australia)
etep, Flight Recorder designerHeavy Vehicle EDR information site for black box technology
*
IRIG 106 Chapter 10 Flight data recorder digital recorder standard
*
First modern flight recorder "Mata Hari" at display in TampereVapriikki Museum Centre.
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