Flight data recorders are required to be painted bright orange, yet the device is colloquially called a ‘black box’. Early flight recorders consisted of magnetic tape encased in a fireproof box painted black, and the inside of the recorder was pitch black; this dark interior may be the origin of the ‘black box’ name.
Expert behind this article
Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
Why is an airplane black box called a black box?
The term black box refers to a device on airplanes that records flight data and cockpit conversations. Although the device is actually two separate pieces of equipment - the Flight Data Recorder and the Cockpit Voice Recorder - together they are colloquially called black boxes.
The origin of the label is uncertain. One explanation is that the inside of the recorder was pitch black, since early units were light-tight boxes that housed photographic film. Another possibility is that recovered boxes were charred black after accidents. A third suggestion traces the term to World War II British slang, when secret devices housed in non-reflective black boxes were already known as black boxes. The phrase then migrated to aviation around 1945, after the first flight data recorder was built.
What colour are airplane black boxes?
Airplane black boxes are bright orange in colour. The bright orange colour is officially known as international orange and is selected for high visibility in most environments and under various conditions. Regulations stipulated that all flight recorders must be painted international orange. Early flight recorders were black, but after 1967 the devices were required to be painted bright orange to aid in their recovery after accidents.
How are plane black boxes made?
Manufacturing a black box is done by sheathing the components inside a multi-layer protective shell. The key to manufacturing a successful black box is to make it as indestructible as possible. The outer casing of black boxes is made from materials like titanium or stainless steel. Black boxes are encased in a hardened shell made of titanium or stainless steel and insulated with high-temperature-resistant material. Black boxes have high-temperature insulation of dry-silica material 1 inch thick (2.54 cm). The data storage medium is mounted inside an impact-resistant and fire-resistant container. There are a lot of specialized materials inside them like fireproof covering and shock-proof electronics. The black box contains a thin layer of aluminum around the stack of memory cards. Today's solid-state recorders use stacked memory chips which eliminates moving parts.
Black boxes are heated with a blow torch for an hour at 2,012°F (1,100°C). Units have to withstand a static crushing force of 5,000 lb (2,268 kg) for 5 minutes on each axis. The exterior of the box is coated with a heat-resistant material to protect the data inside from fire and extreme temperatures. 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). The flight data recorder must be watertight to a depth of 20,000 ft (6,096 m) seawater. Each black box is equipped with an Underwater Locator Beacon (ULB) which gets activated in water and emits ultrasonic signals to help locate the device if an aircraft crashes into a body of water.
Are black boxes indestructible?
Black boxes are crash resistant but not indestructible. Each unit is a crash survivable memory unit that can survive an impact of 3,400 g for 6.5 milliseconds, an impact velocity of about 310 mph (500 km/h), fire for at least 60 minutes at 1,100°C (2,012°F), and submersion to a depth of six kilometers (3.73 miles). After retrieval, investigators immerse the boxes in fresh water to prevent salt deposits.
Who invented the aircraft black box?
The invention of the aircraft black box is credited to Australian scientist David Warren, who conceived the idea of a device that records both flight data and cockpit voices in 1953. While working at the Aeronautical Research Laboratories in Melbourne, Warren developed a prototype in the late 1950s.
In the United States, James J. Ryan invented and patented a flight recorder, submitting US patent application 613,670 on 3 October 1956 for an ‘abnormal condition sequence indicating device’. the US Patent Office granted patent 3,074,065 on 15 January 1963. Around the same time, Robert Henry Orgill worked on his own crash-resistant unit, the Orgill Air Safety Unit, from 1945 onward. Robert Henry Orgill tested the black box device in 1956 at Melbourne Airport on 26 February 1957.
The first regulatory step came in April 1941 when the Civil Aeronautics Board required flight recorders, but installation remained limited. Australia became the first country to make installation of both data and voice recorders mandatory in major aircraft, and by the early 1960s the British adopted the Warren device. Production rights for David Warren's device were given to British firm Davall and Sons, which began commercial manufacture.
Do all planes have black boxes?Not all planes have black boxes. Most small privately-owned aircraft, like single-engine Cessnas and Piper Cubs, do not have black boxes because they are not required under aviation regulations. These aircraft are generally below 12,500 pounds (5,670 kg), have fewer than 10 passenger seats, and are not certified to require more than one pilot. Some larger small planes used for charter services or regional flights have black boxes, especially if they are turbine-powered and require two pilots.
Black boxes are required on most U.S. commercial aircraft. 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. An aircraft actually has two black boxes: one is a flight data recorder, and the other is a cockpit voice recorder. The FAA requires commercial aircraft to have voice recorders with at least 25 hours of nonstop recording capacity.
Almost all 4th and 5th generation fighter jets have a flight recorder. Military aircraft, including the B-1B, F-22, T-45, B-2, F-4, F-15, F-16, C-5 Galaxy, NATO AWACS, and the Space Shuttle, have black boxes. Most military aircraft are equipped with a black box called a crash survivable memory unit (CSMU). Some fighters have black boxes, while some older fighter models do not. Helicopters have black boxes similar to airplanes, but they are not always required.
Newer small planes are equipped with lightweight advanced avionics systems that record flight data, though these are not always classified as traditional black boxes. Some aircraft are equipped with a black box deployment system that automatically separates from the aircraft and floats on the surface, like the F-18.
