Re: 737 NACA inlet with moving parts?

From: (Paul Kearney)
Organization: Ireland On-Line
Date:         23 Aug 96 13:45:04 
References:   1 2
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: >The aircon pack inlets below the wing root also have articulated
: >doors on the 73 but rather than vortex generators they have slush deflector
: >doors,
: I've read that some 737-200s were equipped for operating out
: of unimproved airfields.  Supposedly, they were equipped with
: (among other things) air jets at the bottoms of the nacelle
: inlets, to blow debris away from the intakes.  Is this slush
: deflector door part of that package?
: And just how many of these "unimproved-field" -200s (if
: any) did Boeing actually build?

Greetings to one and all.
My understanding is that the changes were based upon a "major-ish mod kit"
it included 2 probes that protruded from under the front nacelle of
each engine which as said blew the debris away and down before the
engine had the power to suck the stuff up into itself and a large plate
attached to the nose-wheel-strut along with smaller nose-wheel doors made up a
plate that stopped any debris thrown up by the nose wheel from
denting/puncturing the skin behind the nose-wheel-well.
(If you've ever seen a 737 like this you'll never forget the size of the
nose-wheel plate ! )

The example shown to me was of a field made of "gravel" (as opposed to
asphalt/concrete) where pitting of the fuselage woudl result along with
mega-blade-loss from ingestion of the gravel itself.

The doors on the air condx ducts are powered for different levels of required
outside air and I think theyre controlled by the air condx packs
but I wont put any money on it :-)

The orignal message of this thread was enquiring about the apu deflector
vain/door  which pops out into the airflow when the apu is switched on.

Spanner? What Spanner ?