what makes an aircraft's crash black box indestructible??

[tom d. friedman]

all mass civilian, public, & military / govt aircraft carries a crash black box worldwide. what material is used to protect the inner components?? every crash where it is searched for is obviously a disaster. the box survives any crash scenario, even under water & regardless of conditions. why can't the technology with the material used be put forward beyond that??

[Pat]

I've never seen the inside of one, but I don't think they're totally indestructible. They are located toward the rear of the aircraft , so they're a little less susceptible to damage in the event of a crash. BTW, they're not black (on Boeings, anyway), they're orange or red, IIRC.

[JDK]

Good question! I dunno the answer, but I know some of it!

When I returned to Australia, I discovered they were invented and developed by an Australian, and there's a book out there all about it (which I've not read!). Firstly they don't always survive, but are built tough to survive most likely scenarios, I'm not sure if making them orange has a positive effect on their chances of survival, but it helps in getting them found.

They are nicknamed called 'black boxes' because their contents are a mystery, (black = covert) rather than they were ever that colour. The proper name is flight data recorder, and IIRC they're basically a development of the W.W.II era wire recorders, which are a tougher version of tape records we pre-digital age guys will understand. For the kiddies, "it's all done by magic".

And for some more, more likely data: http://en.wikipedia.org/wiki/Flight_recorder

http://en.wikipedia.org/wiki/List_of_un ... _recorders

And for the question of why they don't make aeroplanes out of black box stuff - the other answer is because people are squishy and vulnerable to the wrong amounts of stuff like oxygen and water.

[JDK]

Some stuff about the inventor here, which interestingly links back to an early accident with de Havilland's awful airliner the DH.86 Express - a dog of a plane.

http://www.dsto.defence.gov.au/page/3384/

http://www.abc.net.au/dimensions/dimens ... 850016.htm

The book: "Black Box: David Warren and the Creation of the Cockpit Voice Recorder" by Janice Peterson Witham (073440770X)

[Ken]

Most of today's transport aircraft will sport at least two orange boxes; a CVR (cockpit voice recorder) and DFDR (digital flight data recorder). I'm not as familiar with the newest types, such as B-737-900, B-777, or the Airbus series - not sure how many boxes they utilize.

[plankwings]

The latest models are solid state. The data is collected by a DFDAU, or digital flt data aquisition unit and saved on microchips in the unit. The latest unit replaced a magnetic tape unit(much like an old audio cassette) encased in a "stainless steel armoured shell". They can withstand huge G forces and temperatures, albeit for a very short time.

Plankwings

[Mgawa]

This box is made of titanium, 5 cm thick walls. Small and compact, it can resist crash as well to stay deep under water for some longer time.

[warbird1]

Black boxes are not indestructible, and they sometimes get destroyed by the impact, but not often. For example, the black boxes for the two airliners that hit the World Trade Center on 9-11 were destroyed and never recovered.

A better way to characterize black boxes is that they are "crash-resistant" but not "indestructible".

[Kyleb]

I saw a NOVA or Discovery channel special on black boxes once.

As others have pointed out, the shell is crash resistant and water tight. Black boxes are usually located in the aft fuselage where any impact would be cushioned by the remainder of the airframe accordioning. In addition, the electronics are shock resistant. Beyond that, there is a thick mass of wax (or some wax like substance) that fills the cavity between the outer shell and the inner shell. In the case of fire, the melting of the wax absorbs a lot of heat energy, hopefully allowing the black box to survive many fires.

The bottom line is that a black box is a layered system designed to sacrifice itself in order to protect the data - which is the only important part.

[JDK]

Black boxes are not indestructible, and they sometimes get destroyed by the impact, but not often. For example, the black boxes for the two airliners that hit the World Trade Center on 9-11 were destroyed and never recovered.

No, actually it's part of the giant conspiracy, and they've been hidden by some men in black*. See the link I posted above about the unrecovered / lost flight recorders.


*Joke.

[John Dupre]

I think that the term "Black Box" is a generic term to describe most aviation electronics components which are usually painted black. I am not certain but it may be that early cockpit and flight data recorders were black. In any event the term Black Box predates the development of the data recorders anyway. Most avionics components were in black boxes but since in a crash investigation they were rarely of as much importance as the data recorders and the popular press doesn't know its a** from a hole in the ground regarding aviation (and increasingly anything else these days) the generic term has become a specific one regarding the data recorders even though they have been orange for many years. Go figure.

[JDK]

I think that the term "Black Box" is...

...Go figure.

Have a look at the links I referenced earlier in the thread which discuss the origins of the term.

Regards,

[oscardeuce]

Adamantium infused with Vibranium.