Density altitude is defined as which of the following?

• A. The altitude above sea level adjusted for temperature only
• B. The altitude in the standard atmosphere corresponding to the current air density
• C. The pressure altitude corrected for humidity
• D. The actual height above ground level

Answer: (B)

Density altitude is the altitude in the standard atmosphere that would have the same air density as the air currently present. This ties directly to how air density—controlled by pressure, temperature, and humidity—affects lift, thrust, and engine performance. When conditions make air less dense (hot temperatures, high humidity, or lower pressure), the density altitude is higher than your true altitude, meaning performance is as if you were higher up (longer takeoff distance, slower climb). In colder, denser air or higher pressure, the density altitude is lower, improving performance.

The option describing the altitude in the standard atmosphere corresponding to the current air density is the correct one because it directly defines density altitude in terms of matching current density to a standard-atmosphere height. The other statements don’t capture that relationship: altitude adjusted for temperature only ignores density changes from pressure and humidity; humidity-corrected pressure altitude isn’t the same as density altitude, which uses actual air density; and actual height above ground level has nothing to do with air density.