Re: Swissair MD-11 (SR 111, JFK-GVA) crash off Nova Scotia

Date:         26 Oct 98 02:59:42 
From:         k_ish <>
Organization: ICGNetcom
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JF Mezei wrote:

> Anonymous lo14 wrote:
> > Some *cargo* compartments depend on a lack of oxygen to snuff out a
> > fire, but no passenger compartment can do that.  That's because those
> > cargo compartments are inaccessible in flight.  You fight passenger
> > cabin fires with fire extinguishers.
> In the case of the DC-9 (Valuejet), it was considered a Class-D cargo
> compartment which, if I remember correctly, assumes air starvation as
> method of extinguishing, right ?

Don't recall if it is self extinguishing, or will not support the spread or
propigation of a fire.  Need to look up FAR25.

> But the DC-9 also vents cabin air through holes in the cabin floor
> alongside the walls, and that air goes to the cargo hold (one of which
> is heated).  So I wonder how it can starve a cago fire of air unless it
> stops pumping air in the cabin.

If we assume the self-extinguishing / air starvation method is correct, I
would assume the available vent area between the cabin and cargo hold is
lower than the air requirements of a sizable fire.  In other words, oxygen
will be consumed by the fire (and at the same time be displaced by
combustion gasses) faster than it can be supplied from the cabin.  In the
case of ValuJet, the oxygen was supplied by the O2 generators.

Ken Ishiguro