If the pressure altitude is 5,000 ft and the true air temperature is +25 °C, what is the density altitude approximately?

To determine the density altitude, we start by understanding the relationship between pressure altitude, true air temperature, and density altitude. Density altitude is affected by temperature deviations from standard conditions. As temperature increases, density decreases, which raises density altitude.

In this scenario, the pressure altitude is 5,000 feet. The standard temperature at 5,000 feet is approximately +15 °C. However, the actual true air temperature is +25 °C, which is 10 °C higher than the standard temperature. Each degree Celsius above standard temperature typically raises the density altitude by about 120 feet.

Calculating this gives:

1. Calculate the deviation from standard temperature:

• Actual temperature = +25 °C

• Standard temperature at 5,000 feet = +15 °C

• Temperature deviation = +25 °C - (+15 °C) = +10 °C

2. Convert the temperature deviation to feet:

• Increase in density altitude = Temperature deviation (in °C) × 120 feet/°C

• Increase = 10 °C × 120 feet/°C = 1,200 feet

3. Add the increase to the pressure altitude:

• Density altitude =