124 PERFORMANCE, STABILITY, DYNAMICS, AND CONTROL
From Eq. (2.196), we obtain the load factorin turn as
L
n: W
1
== N
COS ,L .
The flight velocity is given by
V-
(2.198)
(2.199)
For turning flight, the load factor n depends on the bank angle. The higher the
bank angle, the higher the load factor that will be developed in turn. Dividing Eq.
(2.197) by Eq. (2.196) we get
\/2 Tsinp
tanp, = Rg - - W (2.200)
The radius of curvature R and rate of tum to are given by
1/2
R=g~t -.+-.p-)
V
co = R
=g(tanru+ p-)
V .
T sin p
- g tan,L+ -
W
The tune for one complete turn of 27r radians is given by
27r
t2r = ~
to
(2.201)
(2.202)
(2.203)
The important metrics of turning performance are the turn rate or the angular
velocity in turn co and the radius of turn R. From the above equations, we observe
that the aircraft with smaller values ofwing loading W/S wiD have higher tum rates
and a lower radius of turn, everything else being equal. Notice that the expressions
AIRCRAFT PERFORMANCE
125
for load factor n, rate of tuni co, and radius of tum R do not explicitly contain
the drag term. It is implied that for these relations to be true, the thrust available
balances the drag as given by Eq. (2.195).
We also observe that sideslip helps the turning flight because of the availability
ofa thrustcomponent T sin }3, which provides part.ofthe centripetal force as shown
in Fig. 2.26. However, this benefit may be slightly offset because of the additional
drag experienced by the aircraft in sideslip.
2.8.3 Coordinated Turning Flight in Horizontal Ptane
Let us consider a steady, coordinated turning flight in a horizontal plane. By
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