alt. static.

On Nov 2, 3:55 pm, Andrew Sarangan wrote:
On Nov 1, 12:58 am, wrote:

I was preparing to fly a cessna 172SP the other day and as I usually
do I pulled the alt.static expecting a small wiggle in the gauges. And
got nothing. This was the first time I i got no response from the
gauges. I was told by somebody at the front desk this was common and
that many of the 172's show no movement at all. But.. if this is so..
how can I be certain the alt.static would work when I needed it.

Thanks in advance.

I have seen some airplanes show a small wiggle, and some that don't
when the static port is turned on or off. There is no easy way to
positively verify that your alternate static is working. If you are up
to it, you could suck on the static port and ask someone to verify
whether the VSI is showing a climb. Then repeat with the alt static
open. The latter should not show a climb. Or get a suction for this
purpose. Just a thought. I have never done it this way.

To clarify i have flown - rented - this aircraft a lot and it always
wiggled. The aircraft is a 172SP.

I would not cancel a VFR flight in the area for the lack of
alt.static, but as my CFI said - I asked him this question too - IFR
would be a different story.