Re: TWA 800 technical question.

Date:         04 Jun 97 01:45:43 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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>1- Has the NTSB concluded that the "incident" began INSIDE the central
>   fuel tank, or has it only concluded that as part of the destruction,
>   the central fuel tank exploded and that the source of explosion was
>   near or at the central fuel tank ?

The pedantic answer is that the NTSB has reached no conclusions at all
yet.  Their informal comments indicate that they are certain, or very
nearly so, that they breakup of the aircraft began with an explosion
inside the center fuel tank.  They have no evidence to support any of
the theories regarding what sort of event might have triggered that
explosion -- theories involving both internal and external triggering
events remain consistent with available evidence, at least according
to public comments.

>Is it potentially/conceptually possible that a ruptured hot bleed air
>tube would have heated the central fuel tank to a point where the
>pressure inside the tank caused by increased temperature and expansion
>of the air inside would have caused a rupture at a weak point in the
>tank, causing a fuel leak ?

Probably not, since the fuel tanks are vented.  (The information
released so far mentions sooting of one of these vent lines from the
starboard wing.)

> - Are the central fuel tanks capable of being pressurized or are they
>   by design equalized to the cargo cabin pressure ? (eg: would heating
>   of the tank filled with air cause a higher internal pressure?)

Neither -- the fuel tanks are essentially unpressurized.  They must be
able to withstand some pressure differential, but they are vented to
the outside and thus any pressurization would be minor and temporary.
Cargo holds are part of the pressure vessel and are pressurized to the
same pressure as the main cabin.

Karl Swartz	|Home
Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills