wrote:

begin speculation

Now it could be that after some serial number Cessna changed something
and the later models don't do that, and that would be OK as long as
I have something at least quasi offical to tell me that.

end speculation


Do you have something quasi official that tells you the VSI must wiggle
when alt static is checked on the ground? If so, then your question would
appear to be answered.

Seriously, I suspect that the 172 you're talking about probably does have a
static leak into the cabin. If you want to verify that in order to get it
fixed, flipping to the alt static at speed will be most convincing to
maintenance personnel. Another way to check for a cabin static leak is to
open a window (if allowed) in flight. If your VSI, airspeed and altimeter
needles jump, you've got a leak in the cabin.

On the ground, some aircraft do not experience a perceptable indication due
to the location of the exterior static port.

John Galban=====N4BQ (PA28-180)

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