Rudder Deflections Eyeed in AA587 Probe

AviationNow.com ^ | 10/23/2001 | FRANCES FIORINO

[eno_]

Nice update. The big hint, so far unexplained by any mechanical failure theory, is that the CVR and FDR quit before the plane hit the ground.

[boris]

"View of rear fuselage looking aft shows left center fin lug in left foreground with repair rivets visible."

What view?

--Boris

[Mind-numbed Robot]

If the engines were torn loose, wouldn't power failure account for that or do the recorders have backup batteries?

[Mind-numbed Robot]

What view?

You didn't see it? Must be your browser. :-)

[boris]

"You didn't see it? Must be your browser."

Yeah, but I can see the fnords.

[M. Thatcher]

Photo from original source:

[dighton]

Related item: A300 Uncommanded Rudder Incidents

[Chad]

This photograph is a left side, rearward facing view of the center and aft attachment points for the vertical stabilizer. Look closely at the lower center of the photograph. Note the large, jagged tear through the aircraft's skin which shows the metal bent from the inside out. Also notice the dark, smokish colored residue over the surrounding area.

[drjoe]

Yep. No engines equals no power on buses equals no CVR or FDR. There are no battery b/u's.

[eno_]

I did some digging. You are seemingly correct. Boeings have backup batteries, but there have been documented instances of Airbuses losing recorders temporarily due to low or no power from engines. In this case, the backup air turbine generator would not have had time to deploy and spin up to make power for more than a few seconds, and if the plane was in a spin or a strange orientation it might have done nothing at all. I know this Airbus is not FBW, but I sure hope the FBW Airbuses have battery backup!

[Neets]

Excellent update..thanks for the post.

[mad_as_he$$]

The thing was in a major fire I would expect the hole to act as a chimney!

I saw video of them loading this part onto a truck - right after the fire - it was amazingly intact. But most of it had the burnt residue on it.

[supercat]

The big hint, so far unexplained by any mechanical failure theory, is that the CVR and FDR quit before the plane hit the ground.

Where is the rear black-box mounted on one of those planes? Did it remain with the rest of the aircraft?

[Chad]

Look at the photo again. My point is that all the dark, smokish colored residue is downwind of the gaping hole. It could only have happened that way while on fire in flight, not on the ground.

And look at the gaping hole again...the metal is bent outwards from the inside. Couldn't this mean an explosive force came from within, in flight?

A closer view is provided at the NTSB website

http://www.ntsb.gov/EVENTS/2001/AA587/AA587_10.jpg

Sorry I don't know how to reproduce a blowup here. But check out the photos of the other vertical stabilizer attachment points on the site--you'll see that there is no smoky residue on them, only on the left center and aft ones, near this jagged hole with the metal bent outwards.

[mad_as_he$$]

Ok but IF the picture is looking to the rear I would expect that the attachement point would be pulled back if say it was the last one holding. Also do you know if there was a wind during the fire? I seem to recall that the smoke was moving away at a pretty low angle indicating a nice breeze.

But your observations are interesting I will keep watching for more tidbits in the mess. Thanks

[Chad]

Don't know about any wind on the ground, if that's what you mean. But the above photo shows residue directly downwind (aerodynamically speaking) of the gaping hole.

Also, the above photo does not show any attachment point pulled back, only the aircraft's skin near those attachment points. The skin is directly upwind of the residue.

[Chad]

[Chad]

[mad_as_he$$]

humm pic doesn't want to come up.

[Chad]