Re: passenger stairs in aircraft tail

From: (Brian A. Reynolds)
Organization: Rockwell Avionics - Collins, Cedar Rapids, IA
Date:         17 Jul 95 04:29:35 
References:   1 2 3
Followups:    1
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The rear ventral stairs were added when the number of passengers exceeded the
regulatory passenger/door ratio.  When the DC-9 was lengthened again, the dual
overwing exits were added.  The rear stairs are VERY noisey becasue the two
air-cycle machines used for air-conditioning and pressurization are on either
side of the stairs as you use them.

The 'strong kerosene' smell is due to the APU being mounted above the stairs
with it's exhaust exiting from the aircrafts right, again in the area of the
stairs.  When closed, the stairs retract upwards, but the ceiling comes down
until it it on top of the stairs.  This forms the emergency 'passage' from the
pressure door out to the slide area.  The slide, incidently, is automatically
deployed by a lanyard pulled when the tail cone drops.  The lanyard, in
addition to causing the slide to inflate, also causes the tailcone to be pulled
to one side, out of the way of the slide.

For the D.B. Cooper fans, the FAA required all ventril stairs to be disabled
unless there is weight on wheels.  This prevents someone from using it as a
parachute exit.