Commercial Pilot Airplane (CAX) Calculations Practice Exam 2026 - Free Pilot License Practice Questions and Study Guide

To determine the density altitude, it's important to understand the relationship between pressure altitude, temperature, and how they affect air density. Pressure altitude is the height of an airplane above a standard datum plane, which is typically set at 29.92 inHg. When the true air temperature deviates from the standard temperature for that pressure altitude, the density altitude will be impacted.

In this scenario, we start with a pressure altitude of 6,000 feet. The standard temperature at this altitude is about +15 °C (or +59 °F). However, since the temperature given is +30 °F, which translates to approximately -1 °C, it is significantly warmer than the standard value.

To calculate the density altitude, we consider the deviation of the true air temperature from the standard temperature. Warmer temperatures decrease air density, thus increasing density altitude. A temperature of +30 °F is about 11 °F above the standard temperature for this altitude.

Using the approximate rule of thumb, every degree Fahrenheit above the standard temperature increases the density altitude by about 120 feet. Since the temperature is around 11 degrees above standard, we would calculate an increase of about 1,320 feet (11 degrees * 120 feet per degree