Page 288 - Planning and Design of Airports

Geometric Design of the Airfield 249

Since this is less than 50° the radius is adequate.
From Eq. (6-12), we have

F = (R + d − 2Rd sin A ) − 0.5u − M
2
2
0.5
max
or
0.5
2
2
F = [150 + 72.1 −(2)(150)(72.1) sin 29°] − 0.5(34.25) − 15
F = 100.1 ft
From Eq. (6-12),

dln(4 dtan . 0 5 A )
L = max − d
W −− 2 M
u

( )(
⎡ 472 1 . )(tan 14 5 . ° ⎤ )
L = 72 1 .ln ⎢ ⎥ −72 1.
− 2 15) ⎦
.
⎣ 75 − 34 25 ( )( ⎦
or
L = 68 ft
Therefore, both the required fillet radius and the required length of the lead-in
to the fillet for this specific aircraft are both well within those recommended for
the airplane design group to which this aircraft is assigned.

End-Around Taxiways
In an effort to reduce the number of times aircraft must cross a run-
way when traveling around an airfield, the FAA has allowed for the
design of taxiways that traverse beyond runway thresholds. These
taxiways, known as end-around taxiways, are designed to both
reduce the risk of runway incursions and increase the overall effi-
ciency operations on the airfield. For safety considerations, primarily
concerned with the transient presence of aircraft immediately off the
end of the runway, the FAA has established specific design standards
for end-around taxiways. An example of end-around taxiway con-
figuration is shown in Fig. 6-38.
End-around taxiways must remain outside of the runway safety
area, and outside of any ILS critical areas. In addition, the tail height
of the critical design aircraft at the airport must not exceed any criti-
cal Part 77 or TERPS surfaces, when on the end-around taxiway. Fur-
thermore, the location of the end-around taxiway should provide for
any aircraft departing on the runway to clear any object on the taxi-
way by at least 35 ft vertically and 200 ft horizontally from the run-
way centerline.