You reset your altimeter to match local, nonstandard station pressure readings, using the Kollsman window on your altimeter. This is usually done every 100NM for aircraft flying below FL180.
People Also Ask
Aircraft altimeters are subject to the following errors and weather factors: Instrument error.Position error from aircraft static pressure systems.Nonstandard atmospheric pressure.
Can you take off without a functioning altimeter? No. As answered elsewhere, FAR part 91 defines the minimum equipment required for flight (airspeed, altitude, compass, power). it is currently a legal requirement to have an altimeter in your airplane.