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Old April 3rd 07, 10:26 AM posted to rec.aviation.piloting
Neil Gould
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Posts: 723
Default Altimeter Calibration Height

Recently, Steven P. McNicoll posted:

"Neil Gould" wrote in message
et...

Perhaps you misunderstood Jose's example, but I believe he's correct;
while an altimeter senses the pressure at the level of the
insturment, it *indicates* the calibration set by either the shop
(e.g. compensating for the altitude of the installation) or the
pilot via the Kollsman window.


I understood it, I didn't say he was wrong.

Perhaps I misunderstood your response.

Jose stated:
[...] An altimeter indicates whatever it is set to indicate.

[...]

and:
If you don't get an altimeter setting, you will (likely) set the
altimeter so that the hands indicate the airport elevation as
indicated on your charts, even though you and the instrument are a
hundred feet higher.

If you do get an altimeter setting, you'll set it for that. Then the
question becomes (since the altimeter doesn't know that it's in a
tall airplane) whether, at calibration in the shop, it was set to
indicate actual instrument altitude or to indicate something else
(like instrument altitude minus a hundred feet).

[...]

To which you replied:

In other words, an altimeter indicates altitude at the level of the
instrument itself.

How do you reconcile your comment against Jose's statements? Both
statements will only be true under a very limited set of circumstances
that I would think excludes "In other words...".

Neil