Black box recorders: 9/11

yew_tree

I was watching an interesting documentary the other night on the issue of the black box recorders not being found from the aircraft that hit the twin towers.

Now I am no conspiracy nut but I found myself questioning the official line.

The official line given by the 9/11 commission is that no black boxes were found.
A retired pilot and crash investigator claimed that in his 30 years - they never failed to find a black box at a crash scene, they have even pulled them up from the bottom of the sea.

In the months after the attacks, they brushed through the site and even human bone fragments the thickness of your finger nail were found and identified. I am beginning to find it very hard to believe that two (or four) long orange boxes built to withstand extreme conditions were not found or at least part of them.

Can any aircraft experts in here offer an explanation?

dogmatix

The heat from the jet fuel was intense and the fires burned for a long time before the towers collapsed. I'd imagine that any black box would be rated to survive burning for only a specified time before failing and being consumed. Then the black boxes fell a 1000 feet or more before being crushed under many thousands of tons of concrete and steel. I'm not surprised they found anything to be honest.

Stovepipe

Hi there,
What came out of the conveyer belt search system set up to process the rubble afterwards was that falling concrete and steel is a perfect grinding machine. Humans were ground down to fingernails and minor bones (again, not a new finding; it happens in air crashes) and seemingly indestrucible steel structures were shredded. A black box is really only a small, strong can and considering the impact, fuel explosions, falling to the ground inside a huge grinding mass of concrete, steel, glass and millions of pieces of everything inside the buildings, it'd be a miracle if they survived. It's not unknown for them to be destroyed in non-building air crashes,too. Quite often, the data is kept on hard discs and that survives. also, modern airliners continually transmit their inflight computer data to the airline, the aircraft manufacturer and the engine manufacturer, so the DFDR is essentially only a back-up.

regards
Stovepipe

yew_tree

Stovepipe - Interesting - I guess in any industry you will find people with different opinions. The documentary also featured a guy called Joe malone - a rescue worker who spent 267 straight days at ground zero working through the rubble. He claims the black boxes were found but was told by FBI not to say anything....but I guess that is entering the whole conspiracy issue which nobody can prove it seems.

bluecode

They found the flight recorders of the other two aircraft. The Pentagon one was unusable and a transcript of the other was released.

Clearly the other two were destroyed in the fire and collapse. It's something of a myth that they're indestructible. The so called expert should know that.

Of course if they had been found they would probably have provided nothing useful. Even if they did the conspiracy nuts would called it fake.

There is no reasoning with these people.

martinsvi

I guess in this case we don't really care about FDR as that information can be estimated, we would only care about CVRs.. so if it's recovered, then what? Do we expect the terrorists to discuss their pay-checks and where it came from in perfect English?

weisses

Well at least they found the passport from 1 of the hijackers :rolleyes: