Your aircraft is at an indicated altitude of 2,200 ft. The altimeter setting is 29.62 inHg and the outside temperature is +20 degrees Celsius. What is the density altitude?

To determine the density altitude, it is essential to understand how both pressure and temperature affect the air density at a given altitude. The formula for calculating density altitude involves using the pressure altitude and adjusting it for the non-standard temperature.

First, the indicated altitude of 2,200 feet corresponds to the pressure altitude when the altimeter is set correctly to the local altimeter setting. In this case, the altimeter setting is 29.62 inHg, which can be converted to pressure altitude, but since it is set appropriately, it remains at 2,200 feet.

Next, to find the temperature deviation from standard, we need to know that the standard temperature at sea level is 15 degrees Celsius. For every 1,000 feet of elevation, the standard temperature decreases by approximately 2 degrees Celsius. Therefore, at 2,200 feet, the standard temperature is calculated as follows:

15°C - (2°C x 2.2) = 15°C - 4.4°C = 10.6°C

Since the outside temperature is +20 degrees Celsius, it is evident that the actual temperature is warmer than the standard temperature at that altitude.

To find the density altitude, we need to apply the correction