After the ambulances and firetrucks have left the scene of an aircraft disaster, investigators pour over the wreckage seeking the little “black box” which everyone has heard of, but few know its history. The Malaysian Airlines flight from Kuala Lumpur to Beijing which has disappeared over the South China Sea also has a black box onboard. Once it’s found, it may provide clues as to why the plane went down, possibly killing all 239 people.
Often known as a black box an airplane’s flight recorder is technically called a “cockpit voice recorder” or CVR. The device is usually located int he tail section of the plane to help increase the odds of surviving a crash. Equipped with microphones, early black boxes only recorded sounds emanating in the airplane’s flight deck.
While a modern-day black box is painted bright orange to help investigators find them, early versions were painted black, and the name stuck. Built in a multilayer construction method, modern black boxes are double wrapped in a corrosion-resistant stainless steel container with high-temperature insulation.
The earliest commercially used black boxes were developed in Australia in the 1950s. At first, they were only used on some aircraft and it was left up to the airline whether to have them installed or not. During the 1960 investigation of Trans Australia Flight 538, the recommendation was made that flight recorders be installed on all airlines, making Australia the first country to require their use. The United States’ first CVR rules were passed in 1964 and required all planes with four or more engines to have them installed.
The earliest cockpit sound recorder, and painted black, was a black box was developed by Edmund Boniface, an engineer with Lockheed, in 1961. His patent, Number 3,327,067, was challenged in court by pilots were alarmed that the device was an “invasion of privacy.”
At first, black boxes were equipped with a toggle switch that would allow the pilot to erase the recording at the end of a safe flight. As accident investigations grew in number and sophistication, investigators started wondering about the conversations between pilot and co-pilot as well as other collateral sounds before and during crashes. Boniface responded with a device that was in a sealed container and shock-mounted and sealed to avoid the high temperatures expected during a crash fire.
Early black box devices got their information from microphones positioned in random places inside the cockpit and were analog devices. Wire recording was first used and then replaced with an endless looped tape, similar to 8-track cartridges. Analog recording was replaced by digital and this switch allowed for longer recording time as well as sturdier equipment.
The US National Transportation Safety board is currently looking into the use of flight deck imaging in large aircraft. The images provided would supplement the CVR and FDR data now available.
The image recorders are expected to cost $6,000 and would include a mini-cam and built-in microphone in the cockpit to record instrumentation, exterior viewing devices around the cockpit and ambient sounds.
Legislation is currently pending in the US House of Representatives to require aircraft manufacturers to install an additional cockpit voice recorder. The second CVR would be a system that would be deployed from the tail of the plane during impact.
The non-profit theatrical group, Collective Unconscious, produced Charlie Victor Romeo in New York City which was based on transcribings from black box recordings of several flight emergencies. The play featured the United Airlines Flight 232 which ended near Sioux City, Iowa.
By Jerry Nelson