Density altitude is pressure altitude corrected for nonstandard temperature.
Density altitude is an indicator of aircraft performance and should be calculated before any flight as if its high, it reduces lift and impairs propeller efficiency, reducing thrust as a result.
Formula to calculate density altitude.
- Pressure altitude is determined by setting the altimeter to 29.92 and reading the altitude indicated on the altimeter.
- OAT stands for outside air temperature (in degrees Celsius).
- ISA stands for standard temperature (in degrees Celsius).
Example:
If the standard temperature is 17 degrees and your outside temperature is 20 degrees celsius, calculate the density altitude if your pressure altitude is 1000 Feet above sea level.
Therefore, your pressure altitude is 1,360 Feet.