Pretty much title. I’ve always wondered how those things can withstand massive crashes and explosions and still be reliable to retrieve recordings from.
In: 240
The insulation can withstand temperatures up to 2,030-degrees Fahrenheit. The insulated box is then encased in corrosion-resistant titanium or steel. The thick outer shell protects the interior components from impact, fire, and water.
aerocorner.com
Easy, you don’t have anything living inside to save.
It’s just a data storage device, put it in a fireproof box and design the storage device to handle rapid deceleration.
A human is a fragile thing, can be hurt in many ways. A plane crash kills you by taking your internal organs and smashing them around inside of you and damaging them all.
A black box is just a block of metal, everything inside is solidly attached and nothing inside able rattle around and damage. Nothing alive you need to keep that way. Just an inanimate object you have to prevent catching on fire so you make it out of a material with a higher melting point then what the planes materials get up to when they catch fire.
Metal box, fireproof, waterproof, installed in the tail of the plane. The tail does already survive the majority of impacts. You can’t crash tail first AND going fast. The plane even if loses control entirely, flies like a dart, and crashes nose first. If it goes on flat spin it crashes flat, and that reduced the terminal velocity anyway, so it’s not fast enough to smash the box.
So it’s both construction and positioning.
In addition to lots of really good comments here already, there’s really only one portion of the flight data recorder that *needs* to survive…the memory chips. Most modern FDRs use solid state memory, like a USB stick. Those are very small and *very* durable…outside fire or direct mechanical trauma they’re basically indestructible…you can use similar chips in artillery shells and they can survive the firing process. In the recorder, they’re encased in a large block of fire insulation that’s inside an armored can that’s mounted in the most protected part of the airplane they can find.
Having the whole recorder intact makes getting the data off easier but as long as the memory chips themselves survive you can recover the data…several global investigation agencies (notably the French & Americans) and the FDR manufacturers are *extremely* good at recovering data from even damaged chips.
So in order to lose the data completely you have to crash hard enough to physically crush the airplane structure then the armored can *and* burn it for long enough to compromise the fire insulation. Or just lose the recorder entirely, which sometimes happens…which is why it’s painted blaze orange with reflective stripes and has a sonar “pinger” to help find it if it’s underwater.
Technically they are not “crash proof”, but “crash resistant”. They are built from tough materials, designed to withstand heat and high g-forces, and be water resistant, but there are situations where they simply cannot withstand the extreme conditions of a crash and are either severely damaged or destroyed.
Think of the black box a bit like an egg box. The egg box provides protection above and beyond eggs loose in a bag, but the eggs in an egg box will still break if you drop them from too high a height.
[removed]
Same way a roach can fall 1000 miles and just walk off.
Low weight, low terminal velocity. High tensile strength.
Minimal moving parts and air gaps.
Well, for one, they aren’t puny humies
The main reason crashes are dangerous is because of the way your body is put together
You are a leather sack of jello, with a whole lotta brittle pokey bits, and if that sack (your body) comes to a sudden stop, the jello (organs) keeps moving.
That means organs smack up against your bones, brains get bruised, lungs get pierced by ribs, a whole lotta fun.
Unalike your body, we can design a black box to not have those problems
The thing is basically just a solid brick steel. The computer bits are all encased in insulation so that nothing melts, and nothing can smack against the metal walls.
That said, it still can be destroyed. It’s just a hard to do.
Everyone else is right, but its also just very easy to protect a very small thing. Small things are just safer to drop, hence why a cat or squirrel can fall off a roof or tree and walk away. Drop a human and thats broken bones, and an elephant is going to go splat.
My favorite dad joke is “The flight data recorder was found at the bottom of the ocean still working. Why didn’t they make the rest of the plane out of that stuff?”
Latest Answers