Table 69 



DENSITY-ALTITUDE DIAGRAM 



285 



iKm.) (lOOCr. Ft) 21* 

 -4.5 '5 



This diagram expresses density-altitude (ft.) in the 

 U. S. Standard Atmosphere as a function of barometric 

 pressure (in. Hg.) and virtual temperature (°F.). (Heavy 

 dashed curve shows interrelations of temperature, 

 iressure, and pressure-altitude in the U. S. Standard 

 Atmosphere, where t°F. = 59°— 0.003566Z (Z=piessuie- 

 altitude in feet).) 

 The diagram is based on the following equation which 

 only valid up to 35,332 ft (10.769 Km.): 



H=l 4 S.36 6 [l-(i^^) 023500 ] 



where h = density-altitude in feet, 



Tv = virtual temperature in 'Rankjne, 

 m 459.4* + t, 'F., 

 -- ■ t» — virtual temperature in *F., and 



\Q P = barometric pressure in inches oi 



mercury. 



(Mb.) 700 



lllllllMllllllllllllll 



1 1 1 ■ • ■!■ 1 1 ■! ■ ■ ■ i !• 



10 9 



750 



1....1 



TTTTTTTT, 



7 



24 25 26 27 



BAROMETRIC PRESSURE 

 800 850 900 



|i ■ i ii ■ ■ ■ 1 1 1 ■ i ■ i < ■ 1 1| ■ ■ i • 1 1 1 1 ■ i ■ ■ i ■ 1 1 1 ■ 1 1 ■ 



6 5 4 3 2 



PRESSURE-ALTITUDE (lOOCCs Ft) 



950 



30 ,r u * 31 31 6 

 (In.Hg.) 



1000 1050 (Mb.) 



■'""I I,„.l,l,,ll.lll,,,ll 



2 



SMITHSONIAN METEOROLOGICAL TABLES 



