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LAX
Posts: 2186
Joined: Sun Dec 24, 2000 11:06 am

Black Boxes? Think They Survived Impacts?

Fri Sep 14, 2001 6:22 pm

I heard tonight that the black boxes of the 2 Boeing 767's that were flown through the WTC might not be recoverable.

Too bad. Sure hope they can retrieve them though. I'm sure they would tell us volumes about the last moments of the flights.

But when you see the incredible impact sustained by the two jets, it makes you wonder if EVERYTHING, including everyone on board, didn't just vaporize upon impact.

I've seen the videos over and over, and it's just mind-numbingly tragic!
It appears the jets just flat vanished upon impact! Nothing there at all! Total evaporation.
So how could those boxes survive it. Although I know the Pennsylvania jet (the UA 757) did have its boxes recovered. And it went in almost nose-down.
 
eal401
Posts: 451
Joined: Wed Jul 04, 2001 9:06 pm

RE: Black Boxes? Think They Survived Impacts?

Fri Sep 14, 2001 8:02 pm

If you see the video of the second 767 hitting the tower from the right angle, you can actually see the fuselage burst out from the other side of the building just before the fireball erupts. This appears to have been substantiated by the flight deck of, possibly this aircraft, being found on the roof of a nearby building. It will be a miracle if the black boxes have survived from the two 767s though, first of all they were in the location of an 800-1000 degree fire for over an hour, then buried under tonnes of rubble.
 
Sunken_Lunken
Posts: 87
Joined: Sat Jul 07, 2001 2:48 am

RE: Black Boxes? Think They Survived Impacts?

Fri Sep 14, 2001 11:11 pm

I think it is difficult to say if the recorders survived.

The recorders are designed to withstand an impact force of 3,400 g's, and a 2,000 degree (F) fire for 1 hour. Here is a link to this info:

http://www.howstuffworks.com/black-box4.htm

My prayers and deepest sympathy go out to all victims in these horrible acts of terrorism, as well as their families and friends.
 
captjetblast
Posts: 286
Joined: Thu Aug 30, 2001 5:59 am

CVR/FDR Impact And Fire Test

Sat Sep 15, 2001 3:12 am

Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR)

Impact requirements: 3400G for 6.5ms

Fire test requirements as requested by year:

1958: The recording medium shall remain intact so that intelligence can be analyzed after the recorder has been exposed to flames of 1100 C, enveloping at least 50% of the outsuide area of the case for 30 minutes.

1963: PLUS: Any cracks or holes resulting from the impact shock test be included in the 50% flame envelopment, and that the recorder be allowed to cool naturally

1966: PLUS: Impact shear ~ 500lbs. from 10',1/4" pin adn Static crush ~5000lbs. 3 sides, 5min.

1991: 1100 C, flame enveloping 100% of the outside area of the case for 30 minutes, 50000BTU/h thermal flux.
Note: does not require TSO C124 fire test protocol. (Ref. EUROCAE Doc ED-56)

1992: EXCEPT thermal flux must be measured by a water calorimeter of the size and shape of the recorder. (Ref. EUROCAE Doc. ED-55)

 
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spinkid
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Black Boxes And Survival

Sat Sep 15, 2001 3:42 am

I hold out hope they will be found. So many times during crashes you hear that they wonder if the boxes will be recovered and they do get them. they found TWA 800 and they fished the Valujet one out of a swamp. There was quite a fire in the buildings, but remember there was an explosion. The boxes could have been blown farther out or fallen into the "crater" created inside the building.
While I think it will be difficult. It is certainly within reason that they could be found.
 
H. Simpson
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Joined: Sat Mar 10, 2001 7:30 am

RE: Black Boxes? Think They Survived Impacts?

Sat Sep 15, 2001 5:37 am

Don't forget the collapse of WTC, can those black boxes can be recovered and keep the datas without a scratch under million tons of concrete, a fall of 1,000 feet and buried somewhere in Downtown?

Mike
sorry to those who lost friends and families...from new york Crying