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Why do they call flight data recorders a "black box" if it's orange in color?

Just curious about this since I've seen several images of black boxes but they all come in orange colors, and not black. I can understand orange being used to help brightly identify the box , but then why call it a "black" box?

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6 Answers 6

up vote 11 down vote accepted

The Wikipedia article on Flight recorder offers a possible explanation for the origin of the term:

... they were essentially photograph-based flight recorders since the record was made on a scrolling photographic film. The latent image was made by a thin ray of light deviated by a mirror tilted according to the magnitude of the data to record (altitude, speed, etc.). Since the inside of the recorder was pitch black, this may be the origin of the "black box" name, often used as a synonym for a flight recorder.

Interestingly, the Wikipedia article on Black box claims that the term entered the English language around 1945, which is a few years after the first flight data recorder was built.

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The wikipedia article says the first documented use of black box to refer to FDR is 1958. –  user2168 Jul 24 at 15:40

The correct answer seems to be, "Nobody knows for sure" but here's some data.

The earliest citation in the Oxford English Dictionary for the phrase "black box" referring specifically to a flight data recorder isn't until 1964, from the UK Daily Telegraph: "The flight recorder is an indestructible 'black box' which automatically records the key functions in the aircraft..."

There are earlier uses of the phrase, with different meanings. Since 1932, it has been used to mean a device whose internal workings are unclear but which is specified by its inputs and outputs; since 1945, it has been used in the Royal Air Force to refer to various navigational devices which, according to Wikipedia sometimes were housed in literal boxes that were black.

My interpretation/thoughts/speculation/whatever word you want to use:

The use of quote marks in the Daily Telegraph seems significant. First, it suggests that we're not talking about a literal box which is black and you might imagine they'd say something like " 'black box' (which is now actually orange)" if they were formally literal black boxes. Second, "a 'black box' " suggests that the FDR might be just one of several devices on a plane that could be described as "black boxes". Unfortunately, that seems consistent with both of the other given definitions: you could perfectly well imagine it being RAF-style slang for "This electronic box of tricks does navigation, this one holds the autopilot and this one records flight data" or the input-output version of "I don't know exactly how the autopilot works, but I know what it does; ditto the navigation system; ditto the data recorder."

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Regarding first use to refer to a flight data recorder, Wikipedia says: "The first use of the term 'black box' in reference to flight data recorders and cockpit voice recorders was by Mr E. Newton of the AAIB at a meeting of the Aeronautical Research Council in August 1958.", referring to this document, p.16. Specifically, on August 27 1958, Newton "made the earliest recorded description of the device as a ‘black box’". –  user2168 Jul 24 at 16:22

A black box (generally speaking) is a device or box whose internal working are not of as much interest or value but rather the input and output.

Flight data recorders are orange so that they can be located easily in case of a crash. If they were black, they can be camouflaged by their surroundings.

Bright orange color make them stand out easily, because nature didn't make many things orange, besides oranges.

Another reason is that they are painted/coated with heat-resistant bright orange paint.

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3  
+1 for the update. I suspect that may be the real answer - in electronics it's a common term and from an avionics point of view this is a "don't care" box. The avionics will work fine without it. –  Dan Pichelman Mar 25 at 21:11
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So black doesn't necessarily connotate color but actually conveys the condition of the box? –  thinly veiled question mark Mar 25 at 21:25
    
"Nature didn't make many things orange, besides oranges." Well, apart from various other fruit, lots of flowers, various butterflies, birds, autumn leaves, the sunset, ... (Sunrise, too, I hear but I'm rarely awake then.) –  David Richerby Jul 22 at 21:29

The adjective "black" in "black box" means "opaque". Engineering also uses the phrase "black box testing", which means tests that are done without access to system internals.

Similarly, "white box" means transparent, in which internal signals may be recorded or manipulated.

A black box recorder is presumably recording pilot actions on the system as well as the state shown to the pilot on the instruments, but none of the avionics internal variables. I doubt any modern FDR would be designed this way, however, since without the internal variables diagnosis of failure could be very difficult.

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Actually, I think it's the recorder that is a "black box", rather than the signals being recorded. You don't know how it records the data. You don't normally care how it records the data. In fact you normally don't know or care what data it records. As far as the pilot is concerned, it's just a mysterious piece of avionics which gets tested periodically, gets ignored most of the time, and hopefully will never actually be used. –  keshlam Mar 25 at 23:02
    
When you say that a black box recorder "presumably" does certain things and that you "doubt" that one would do other things, it suggests rather strongly that you're speculating. It also sounds like you're not quite sure what a black box does. –  David Richerby Mar 25 at 23:53
    
@David: This question asks about terminology, I don't think one needs to know about every model of FDR in use. Do you mean to imply that there aren't variations between FDRs in use in different aircraft, different fleets, different countries? (Of course the pilot conversations, actions, and displayed data are recorded, but these are only the minimum data set) I'm not trying to provide the ultimate authoritative answer here, just provide additional context which I feel believe to be helpful. –  Ben Voigt Mar 25 at 23:57
    
@keshlam: That's a good point, although I would say it's not that pilots don't care, but that the recorder functions best when it is opaque and cannot be manipulated by the crew. –  Ben Voigt Mar 26 at 0:00
    
Also a good point. Tamper resistance is a Good Thing if you want to catch and critique the "oops" moments as well as the outright disasters. –  keshlam Mar 26 at 2:46

One other theory I've heard (but been unable to verify) about the origin of the term "black box" in popular literature is that the boxes when found often tend to be black.
Not as a result of being painted black, but as a result of having been inside a burning aircraft wreck, covered in soot and burnt paint.

Whether that's the (or even one of the) reason for the term is probably lost in the mists of time. I seriously doubt it's ever been written down by the people inventing the term (newspaper journalists most likely) what their reasoning was.

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The black box was invented by Professor Gordon Black at Farnborough in 1948 - hence the name 'black' box. See Who really invented the black box?

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-1 Your source is a "did X really invent Y", and it's only an assumption. There are no sources behind it, just guesstimates. Even the validity of the comments is questionable. –  thinly veiled question mark Jul 24 at 3:40
    
Well at least my source makes a lot of sense rather than a lot of the assumptions above that are based on nothing more than someone's personal view –  Les Esling Jul 24 at 7:47

protected by Qantas 94 Heavy Jul 24 at 6:59

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