Page 101 - Planning and Design of Airports

Air craft Characteristics Related to Airport Design 71

Both standard pressure and standard temperature decrease with
increasing altitude above sea level. The following relation establishes the
standard pressure in the troposphere up to a temperature of −69.7°F.

.
P T 5 2561
0 = 0 (2-2)
P T
where P = standard pressure at sea level (29.92 inHg)
0
P = standard pressure at a specified altitude
T = standard temperature at sea level (59°F)
0
T = standard temperature at a specified altitude
In the above formula, the temperature is expressed in “absolute”
or Rankine units. Absolute zero is equal to −459.7°F, 0°F is equal to
459.7°R, and 59°F is equal to 518.7°R.
Using these criteria, the standard temperature at an altitude of
5000 ft is 41.2°F, and the standard pressure is 24.90 inHg. Table 2-7
contains a partial listing of standard temperatures and pressures. It
is common to refer to standard conditions or standard day. A standard

Altitude, Temperature, Pressure, Speed of Sound,
ft çF inHg kn
0 59.0 29.92 661.2
1,000 55.4 28.86 658.9
2,000 51.9 27.82 656.6
3,000 48.3 26.82 654.3
4,000 44.7 25.84 652.0
5,000 41.2 24.90 649.7
6,000 37.6 23.98 647.7
7,000 34.0 23.09 645.1
8,000 30.5 22.23 642.7
9,000 26.9 21.39 640.4
10,000 23.3 20.58 638.0
20,000 −12.2 16.89 626.2
30,000 −47.8 13.76 614.1
40,000 −69.7 8.90 589.2
50,000 −69.7 7.06 576.3
60,000 −69.7 6.41 573.3

TABLE 2-7 Table of Standard Atmospheres