Given a pressure altitude of 12,000 ft and true air temperature of +50 °F, what is the approximate density altitude?

To determine the density altitude given a pressure altitude of 12,000 feet and a true air temperature of +50 °F, one must first understand the relationship between these variables. Density altitude is a measure of the air density relative to standard atmospheric conditions, and it increases with higher temperatures and decreases with lower temperatures.

At standard atmospheric conditions, the temperature at sea level is 59 °F (15 °C), and it decreases at a rate of about 3.5 °F per 1,000 feet of altitude. At 12,000 feet, the standard temperature can be calculated as:

Standard Temperature = 59 °F - (3.5 °F/1,000 ft * 12,000 ft) = 59 °F - 42 °F = 17 °F.

With a true air temperature of +50 °F at 12,000 feet, which is significantly warmer than the standard temperature of 17 °F, we can use this differential to estimate the density altitude. The air is less dense at higher temperatures, meaning that the density altitude will be higher than the pressure altitude of 12,000 feet.

Using a common rule of thumb, the elevation gain in density altitude can be approximated