Index to Math Model Constants

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Entries in the table below define the symbols used in the development of the mathematical model of flight dynamics.

Constants Defined

Constant Description Value
Thrust gain (See Note 1) 2.0
Commanded thrust constant (See Note 1) 0.003
Commanded thrust constant (See Note 1) 0.1
Lift gain (See Note 1) 0.75
Commanded lift constant (See Note 1) 0.01
Commanded lift constant (See Note 1) 0.4
Bank angle gain (See Note 1) 1.0
Commanded bank angle constant (See Note 1) 0.1
Altitude rate gain (See Note 1) 0.1
Maximum bank angle 30.0 degrees
Maximum allowable course change (179/180)π radians
Fuel consumption model constant (See Note 1) 4 x 10-6 slugs/pounds-seconds
Drag model constant (See Note 1) 3.8173 x 10-2
Drag model constant (See Note 1) 2.4789 x 10-2
Lift model constant (See Note 1) 10.0
Lift model constant (See Note 1) 0.5
Mean gravitational acceleration 32.0878 ft/sec2
Pi 3.141592653589793
Eccentricity of the earth ellipsoid 0.0818191908426
Length of earth ellipsoids semimajor axis 6,378,137.0000 meters
Length of earth ellipsoids semiminor axis 6,356,752.3142 meters
Mean Equatorial radius 6,378.077 nautical miles
Sea-level air temperature (ISA) 288.150 °K
Stratospheric isothermal temperature 216.650 °K
Sea-level air pressure (ISA) 1.01325 N/m2
Sea-level air density (ISA) 1.2250 kg/m3
Sea-level gravitational acceleration (ISA) 9.78039 m/sec2
Troposphere temperature gradient, dT/dh (ISA) -0.0065 °K/m
Stratospheres lower altitude limit (ISA) 11,000.0 m
Universal gas constant for air 287.0528 Joules/kg °K
Specific heat ratio for air (ISA) 1.4
Speed of sound at sea-level (ISA) 340.294 meters/sec
Feet per nautical mile 6,076.1155 ft/n.mi.
Nautical mile per foot 1.64578833 x 10-4 n.mi./ft.
Meters per nautical mile 1,852.0 meters/n.mi.
Nautical miles per meter 5.39956803 x 10-4 n.mi./meter

Note 1 - These are nominal values; these constants are not appropriate for all aircraft. Values determining desired behavior may need to adjusted experimentally or estimated from aircraft characteristics.