Altimeter Calibration Height

"Neil Gould" wrote in message
et...

I think the issue is with your use of the term "indicates altitude", which
should be "senses pressure".


It's not an issue with me. Altimeters indicate altitude by sensing
pressure.



The altimeter "indicates" via the display
(dial or digital), and the display is adjustable both during
installation/calibration and by the pilot to adjust for atmospheric
pressure. Consider that when you tell a pilot that the "altimeter is
30.12", the pilot adjusts the _indicated altitude_ by setting the Kollsman
window to that _pressure setting_.


When you tell a pilot "altimeter 3012" the pilot simply adjusts the Kollsman
setting to 3012.



We don't watch the Kollsman (the only
"indication" of "altitude" consistent with the controller's information)
when trying to land. ;-)


Correct.

Recently, Steven P. McNicoll posted:

"Neil Gould" wrote in message
et...

I think the issue is with your use of the term "indicates altitude",
which should be "senses pressure".


It's not an issue with me. Altimeters indicate altitude by sensing
pressure.

Correct, however the "indication" (display) is not the *method* (sensing
pressure). So, your assertion: "In other words, an altimeter indicates
altitude at the level of the instrument itself." is only valid under a few
specific circumstances.

[...] Consider that when you tell a pilot that the "altimeter is
30.12", the pilot adjusts the _indicated altitude_ by setting the
Kollsman window to that _pressure setting_.


When you tell a pilot "altimeter 3012" the pilot simply adjusts the
Kollsman setting to 3012.

Do you see a difference between my statement and yours, other than the
decimal point?

Neil

"Neil Gould" wrote in message
t...

Correct, however the "indication" (display) is not the *method* (sensing
pressure).


Who said it was?



So, your assertion: "In other words, an altimeter indicates
altitude at the level of the instrument itself." is only valid under a few
specific circumstances.


What would those few specific circumstances be?



Do you see a difference between my statement and yours, other than the
decimal point?


Yes. You say the pilot adjusts the indicated altitude, I say he adjusts the
altimeter setting.

It's not an issue with me. Altimeters indicate altitude by sensing
pressure.

Yes, but there's a very important step in between, and that step is the
one that answers the original question.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.