How is density altitude defined?

Density altitude is defined as pressure altitude adjusted for nonstandard temperature. This concept is essential for pilots to understand because density altitude affects aircraft performance, particularly in terms of engine power, lift, and drag.

When temperature increases or pressure decreases, the air becomes less dense. This can negatively impact the performance of an aircraft, as engines generate less power, wings produce less lift, and propellers become less efficient in thinner air. To calculate density altitude, you start with the pressure altitude (the altitude based on a given atmospheric pressure) and adjust it according to the current temperature compared to the standard temperature for that elevation. Thus, the higher the density altitude, the more significant the impact on performance.

Understanding this relationship is critical for pilots to calculate takeoff and landing distances, climb rates, and overall aircraft performance under varying atmospheric conditions.