Page 278 - Planning and Design of Airports

Geometric Design of the Airfield 239

Airplane Design Group
Item Dim. * I II III † IV V VI
Radius of R 75 75 100 150 150 170
taxiway turn ‡

Length of lead- L 50 50 150 250 250 250
in to fillet
Fillet radius F 60 55 55 85 85 85
for tracking
centerline
Fillet radius F 62.5 57.5 68 105 105 110
for judgmental
oversteering
symmetrical
widening §
Fillet radius for F 62.5 57.5 60 97 97 100
judgmental
Oversteering
one side
widening ¶

∗ Letters correspond to the dimensions on Fig. 6-35.
† Airplanes in airplane design group III with a wheelbase equal to or greater than 60 ft
should use a fillet radius of 50 ft.
‡ Dimensions for taxiway fillet designs relate to the radius of taxiway turn specified.
§ The center sketch of Fig. 6-35 displays pavement fillets with symmetrical taxiway
widening.
¶ The lower sketch of Fig. 6-35 displays a pavement fillet with taxiway widening on one
side.

TABLE 6-23 FAA Taxiway Curvature Dimensional Standards, ft

While the rules for flying transport aircraft are relatively precise,
a certain amount of variability among pilots is bound to occur espe-
cially in respect to braking force applied on the runway and the dis-
tance from runway threshold to touchdown. The rapidity and the
manner in which air traffic control can process arrivals is an extremely
important factor in establishing the location of exit taxiways. The
location of exit taxiways is also influenced by the location of the run-
ways relative to the terminal area.
Several mathematical analyses or models have been developed
for optimizing exit locations. While these analyses have been useful