Density altitude is the altitude in the International Standard Atmosphere at which the air density would be equal to the actual air density at the place of observation. "Density Altitude" is the pressure altitude adjusted for non-standard temperature.

Both increase in temperature and increase in humidity cause a reduction in air density. Thus in hot and humid conditions the density altitude at a particular location may be significantly higher than the geometric altitude.

Density altitude can be calculated from atmospheric pressure and temperature (assuming dry air).

$\backslash mathrm\{DA\}\; =\; 145426\; \backslash left*$

where

$\backslash mathrm\{DA\}=$ density altitude
$P\_0=$ atmospheric (static) pressure
$P\_\{SL\}=$ standard sea level atmospheric pressure (1013.25 hpa)
$\backslash mathrm\{T\}=$ true (static) air temperature
$T\_\{SL\}=$ standard sea level air temperature(288.15 K)
$b=$ 0.235

Simpler less acurate method

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Another simpler less acurate method to calculate density altitude is:

DA = ( 29.92 - A) x 100 + 100 ( T - ( 15 - ( 2 x H ) / 1000 ) )

A is the altimeter setting in inches of mercury T is the temperature in degrees Celsius H is the height of the airfield, or aircraft

References

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• Langley Flying School, 2005 Groundschool Manual, page 97, located at Langley Regional Airport

See also

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• Barometric formula

Aviation terminology

Dichtehöhe