Pressure & Altimetry
Pressure & Altimetry is a core knowledge area on the Aviation Weather FAA written exam. This hub collects our 3 in-depth, ACS-aligned pressure & altimetry articles — each written in plain English and grounded in the official FAA handbooks. Work through them below, then drill the topic with practice questions.
Altimeter Errors from Nonstandard Temperature and Pressure
Altimeters read indicated altitude based on standard atmosphere assumptions; nonstandard temperature and pressure cause the instrument to misrepresent your true altitude, with potentially fatal consequences over terrain.
Atmospheric Pressure Explained: Barometers, Millibars, and Inches of Mercury
Atmospheric pressure is the weight of the air column above a surface, measured with barometers in units of millibars, hectopascals, or inches of mercury — and understanding how it varies with altitude and temperature is fundamental to safe altimetry.
The International Standard Atmosphere Model and Its Aviation Reference Values
The International Standard Atmosphere (ISA) provides a fixed reference model of pressure, temperature, and density that calibrates every altimeter in the fleet — understanding its values and limits is essential for safe flight.
More Aviation Weather subjects
Articles are original summaries grounded in the public-domain FAA handbooks and cite their source. ACS-aligned study aids — not a substitute for the official handbooks or regulations.