what are chances of getting the black boxes from the doomed aircraft
The one in PA seems like it’d be pretty easy to get at–no big fire, not much to cover them up.
The ones in WTC 1 and 2 might be a bit harder to find because of the debris, but the black boxes have survived worse. As long as they don’t land in a lake of kerosene and burn for a week, they’re usually readable. Unless they ended up directly beneath a big piece of structural steel that fell almost a quarter of a mile…
Finding the foot-square boxes under 200,000 tons of steel and 435,000 cubic yards of concrete* might be a problem.
[sub]*–numbers from the official Port Authority WTC website.
I don’t think there will be much left of the two from the WTC towers or the one from the Pentagon. I mean, if the fires were hot enough to melt the steel support structures(a current hypothesis of experts on the collapse of the towers) then what would be the chances for the survival of the black boxes? Slim to nil.
Sure, they are relatively fire-resistant provided that they are not continuously incinerated in a veritable furnace for hours on end, as they were in the WTC towers, then subjected to a high altitude fall and pummled by thousands of tons of debris.
The best bet of retrieving a black box will be from the Pittsburgh crash.
Building a Better Black Box by Mark Alpert at Scientific American.
Chances are pretty good that some part of the solid state electronics will be salvageable even if the hardened case has been breached. These things are designed to survive catastrophic disasters.
But finding one under a gazillion tons of debris…do they have any kind of homing beacons? And if so, are they likely to be working under these conditions?
Read the link I provided. The activator beacon only works under water. In a ground crash, they can be located with metal detectors - or by sight alone since they are brightly colored. The search around on land is usually only a few acres. Underwater, it could be hundreds of square miles.
“Their survival rate has greatly improved in recent years as the FAA has raised the certification requirements. Although older recorders using magnetic tape were susceptible to fire damage, no solid-state device has been destroyed in an accident to date.” - evilhanz’s link
Good news!
Then isn’t their name a bit of a misnomer?
Not really. “Black Box” is more a reference to their function than their color. A black box is a device with a predictable, reliable function, whose internal mechanisms are mysterious or unknown.
FWIW, “black boxes” are orange.
Some black boxes (more specifically, cockpit voice recorders).
Neato. Thanks for the link. I had no idea what they looked like.
I expect that we will find the ones from the WTC sooner or later. They’re probably made of tougher stuff than the WTC. (For the same reason that we don’t make whole airplanes out of the same materials we make black boxes out of.)
The Master’s answer to the question:
If aircraft “black boxes” are indestructible, why can’t the whole plane be made from the same material?
DrMatrix - acutally that column is somewhat out of date.
Have you seen the footage from PA? There is almost zero visible debris. It appears that the plane slammed into the ground at an almost vertical angle. They quoted someone as saying that there were no pieces larger than a phone book intact. So it may be more difficult than we thought.
And there has been speculation that the terrorists may have pulled the circuit breakers to the boxes, which will prevent any recordings. OTOH, there has reportedly been intercepts of cell phone conversations between some of the terrorists on the plane and ground support. Thank you NSA.
I remember reading FDR’s are on a seperate power system. I don’t think pulling circuit breakers is going to stop it from working. The links do record power requirements though, so I don’t know how they are powered.