Could it be possible that the cabin roof vent from the tail has an
opening to the empennage and that pressurizes the empennage when you
close the flapper to the overhead outlets? There would also have to be
something blocking the wall grille on the left side of the cabin. The
impact air at cruise may be at high enough volume and pressure to
overwhelm the belly exit vent and the residual volume flows backward
into the cabin via the right wall grille.

Just a thought based on what I've seen in this thread so far.



-----Original Message-----
From: Roy N5804F ]
Posted At: Tuesday, January 16, 2007 6:28 PM
Posted To: rec.aviation.owning
Conversation: Piper Archer II Air Leak Problem by Back Seat.
Subject: Piper Archer II Air Leak Problem by Back Seat.


Good point there Jim,
Unfortunately both of the fine mesh vents in the rear seat plank are
not
connected to ducts at all.
They just vent cabin air to the area under the seat plank and from
there
the
stale air should vent via the central belly hole.
But you may have hit on a point.
Although the vents are not ducted I will check if I can see how the
air
might flow under the plank.

Thanks
Roy



"Jim" wrote in message
...

Does anybody know the shape of the connection where the left and
right
sides
join before exiting the outlet? "T"? "Y"?
Could it be shaped so that the rushing air escaping from the left
side
is
creating a low pressure area inside the tube on the right side
causing
air
to enter the exit port and flow into the right side? Like a shallow
well
pump forces some water down the well through a venturi to force more
water
up the well. What happens if you put some duct tape over the outlet
opening
on the bottom of the plane?
Jim

"Jay Honeck" wrote in message
oups.com...
The outboard floor vents are connected to the wing root openings.

The heater vents run along the center tunnel between the seats.

The overhead vents connect to the vertical stabilizer opening
with
the
blower in between.

Yep, but he's not talking about ANY of those vents.

There is a fine grating piece that fits alongside the rear seats,
between the seat and the outer wall of this model of Cherokee.
This
grating allows air to flow freely the cabin and the under-seat
compartment (where the battery is on some Cherokees), and then out
a
hole in the bottom of the plane.

Think "flow-through ventilation", circa Pontiac 1968.

That hole has a shroud around it that makes it act like a venturi
in
flight, actually SUCKING the air through those mesh grates, and out
the
bottom of the plane. For some reason, the OP is getting air coming
OUT
of that grating -- only on the right side -- which is seemingly
impossible.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"