"fudog50" wrote in message
...
snip

IIRC, the only indicator that had both pitot and static inputs
was the VSI/Rate of climb indicator and the internal bellows in the
gauge performed the differential action.

Ok, what they taught me was that the VSI ran on static pressure and
*metered* static pressure.

I'm not aware that pitot pressure (which is directly related to
airspeed) would be of use for a VSI.
Can you explain how that would be used in a VSI? I can't see any
connection.

The only time pitot pressure = static pressure is if the aircraft is
stationary and there is no wind.

The difference between static port pressure and static pressure that was
restricted as to the rate it
could alter (inside the VSI) by way of a port that is very small in
comparision to the main static port gives
the rate that pressure (and therefore altitude) is changing, giving you
a rate of climb or descent.

Airspeed has pitot inputs only.

ISTR that an ASI that can give you a TAS instead of an IAS had static
pressure and temp sensors
in addition to the pitot inputs, *or* it was in some way
coupled to the altimeter, so that it could show a corrected TAS based on
density
altitude, but I've never actually had one in my hand. IIRC, a PA28-180R
I used to fly out
of Broken Hill many years ago had a TAS meter fitted, but I wasn't aware
of exactly how it worked at the time.

Baro Alt. has static port input only.

Yup. An altimeter is basically an aneroid barometer.

Wish I could draw you a
diagram on here, it would explain everything.

It always helps.

The CO