In this episode of Aerodynamic_Poison, we unravel one of aviation’s most deceptively simple—but critically important—instruments: the aircraft altimeter. Pilots depend on it for terrain clearance, traffic separation, and performance calculations—but what happens when it’s just a little off?

We’ll dive into how altimeter settings are derived, why a small error in barometric pressure can put you hundreds of feet off your intended altitude, and how to avoid the dangerous illusion of being “higher than you really are.” You’ll also learn how the five types of altitude—Indicated, True, Absolute, Pressure, and Density—interact to define a pilot’s vertical awareness, and why Density Altitude is the silent performance killer on hot days.

From pressure systems to preflight checks, this episode lays out the practical science behind barometric accuracy—and how pilots translate shifting air into precise altitude readings.