What is the definition of density altitude?

Density altitude is defined as pressure altitude corrected for nonstandard temperature. It represents the altitude at which the air density is equivalent to that at a standard atmosphere—which is defined as a temperature of 15 degrees Celsius at sea level and a pressure of 29.92 inches of mercury.

When this altitude is adjusted for temperature, it provides a more accurate representation of the air density that an aircraft experiences during flight. Higher density altitude indicates reduced air density, which can adversely affect an aircraft's performance, including reduced engine efficiency, lower aerodynamic lift, and reduced climb rates.

Understanding density altitude is especially crucial for pilots because it helps them gauge performance metrics like takeoff distances and climb rates under varying environmental conditions. While temperature-adjusted altitude and pressure altitude are important concepts, they do not capture the full understanding of how temperature affects pressure at different altitudes, which is the essence of density altitude.