The plane does have an alternate static source vented inside; however, I
pushed the valve in to select the exterior port. My guess is that either
this is normal or the static pressure system has a leak.

"Ron Rosenfeld" wrote in message
...
On Fri, 6 Aug 2004 10:11:59 -0400, "Derrick Early"
wrote:

When I close the door to my 172, the airspeed, vsi and altimeter
instruments
jump. Does this mean that I have a leak in my static line? The last check
of the system was 18 to 20 months ago. The last thing that I want is
errors
in altitude while flying IFR.

Do you have an alternate static source that is inside the cabin, and
possible in the wrong position?


--ron