If the little black box on airplanes is indestructible>?

Question

Why don't they make the whole plane out of it? Aren't the lives of people worth it?

Answer 1

There are two main reasons: first, the plane couldn't fly, and second, it would actually make a crash more dangerous rather than less.

The materials that can survive a crash are simply too heavy to make an airplane out of. A plane can only carry so much weight in proportion to its size, and a plane that could survive a crash from cruising altitude would never get off the ground.

But even if it did work, it wouldn't help. The reason people die in plane crashes isn't so much that the plane is destroyed, but that the force of hitting the ground is more than the human body can withstand.

A plane falling out of the sky with nothing holding it up will reach terminal velocity, so assume that the maximum speed of the plane while it falls is constant. When the plane hits the ground, it and everything it it slow down to a complete stop. It takes a certain amount of work (which in physics refers to change in energy) to do that, which is determined by how fast the plane is moving and how much it weighs, so that's a fixed quantity too. But what matters for the people inside is how much force they experience, and force is equal to work divided by distance. So, since work is constant, the only way to make the force smaller is to make the distance larger. That is, it's better to stop over a longer distance rather than a shorter one.

A completely rigid plane that doesn't bend or break when it hits the ground is going to stop virtually instantaneously, so the stopping distance for the passengers inside will be very close to zero, so they experience the maximum possible force. But if the plane is less strong, then the bottom of the plane will stop when it hits the ground, but the rest of the plane above it will keep moving a little, crushing the parts under them. So the passengers start slowing down when the bottom of the plane hits the ground, but don't come to a complete stop until the portion of the plane under them has been crushed by the top. The net result is that they stop over a longer distance, so they experience a smaller maximum force, giving them a better chance of survival.

Obviously that doesn't help a whole lot of the plane bursts into flames, explodes, or whatever else, and even if the plane just hits the ground, people rarely survive, but an "indestructible" plane would actually be more dangerous rather than less for it's very much not indestructible passengers.

Answer 2

you still would get creamed - you ain't made like a black box. Years ago cars were made of thicker heavier sheet metal like a black box and the cars did not crunch like the newer ones and we died when in an accident. Newer cars get creamed to save you using thinner sheet metal and air bags. If a plane were so heavy and had cushions to protect you (best of both) - the darn plane would not get off the ground. Logic says make plane accidents happen less often - that is what the black box tries to help with

Answer 3

I'm going to assume you're being serious.

The black box is a crash-survivable memory unit (CSMU) of the flight data records and cockpit voice records.

They are engineered to be able to withstand extreme pressure, volatile conditions, etc.

Unfortunately, the procedures that make it indestructible, when used on planes, make the planes too heavy/unwieldy to fly.

Answer 4

as far as I know, I believe the location has more to do with it than the material; the material just has to withstand the rest of the plane crumpling around it.

so the box may be tougher than the plane material, but not tougher than hitting the earth without that extra padding. A plane made out of the same material would not have that extra padding.

Answer 5

1) it is not indestructible
2) it is inside the plane usually at the least impact zone of the plane in case of a crash
3) if the plane were made to the same specifications it probably wouldn't be aerodynamic, most likely every plane would crash within seconds of takeoff or before

Answer 6

Too expensive and too large. I have often wondered about Para chutes for the plane if they could get them compact enough.