NAVWEPS 00-8OT-80 
AIRPLANE PERFORMANCE 
important-if not more important-as the 
increased stall speed in turning flight. It is 
important also that any turn be well coordi- 
nated to prevent the increased drag attendant 
to a sideslip. 
TURNING PERFORMANCE. The hori- 
zontal component of lift will equal the centrif- 
ugal force of steady, turning flight. This fact 
allows development of the following relation- 
ships of turning performance: 
turn radius 
P 
r= 11.26 tan 6 
where 
r= turn radius, ft. 
I’= velocity, knots (TAX) 
ti = bank angle, degrees 
ttrrn rate 
ROT= 1,091 tan rb 
V 
where 
ROT=rate of turn, degrees per sec. 
$= bank angle, degrees 
v=velocity, knots, TAS 
These relationships define the turn radius, I, 
and rate of turn, ROT, as functions of the two 
principal variables: bank angle, +, and velocity, 
I’ (TAX). Thus, when the airplane is flown 
in the steady, coordinated turn at specific 
values of bank angle and velocity, the turn 
rate and turn radius are fixed and independent 
of the airplane type. As an example, an air- 
plane in a steady, coordinated turn at a bank 
angle of 45’ and a velocity of 250 knots (TAS) 
would have the following turn performance: 
= 5,550 ft. 
and 
ROT=(I,091)(1.000) 
250 
-4.37 deg. per sec. 
If the airplane were to hold the same angle of 
bank at 500 knots (TAS), the turn radius 
would quadruple (r=22,200 ft.) and the turn 
rate would be one-half the original value 
(ROT=2.19 deg. per sec.). 
Values of turn radius and turn rate versus 
velocity are shown in figure 2.29 for various 
angles of bank and the corresponding load 
factors. The conditions are for the steady, 
coordinated turn at constant altitude but the 
results are applicable for climbing or descend- 
ing flight when the angle of climb or descent 
is relatively small. While the effect of alti- 
tude on turning performance is not immediately 
apparent from these curves, the principal effect 
must be appreciated as an increased true air- 
speed (TAX) for a given equivalent airspeed 
(EAS). 
TACTICAL PERFORMANCE. Many tac- 
tical maneuvers require the use of the maxi- 
mum turning capability of the airplane. The 
maximum turning capability of an airplane will 
be defined by three factors: 
(1) Maximum lift capability. The combi- 
nation of maximum lift coefIicient, C,,=, 
and wing loading, W/S, will define the 
ability of the airplane to develop aero- 
dynamically the load factors of maneuvering 
flight. 
(2) Optrating ftrcngth limits will define the 
upper limits of maneuvering load factors 
which will not damage the primary struc- 
ture of the airplane. These limits must not 
be exceeded in normal operations because of 
the possibility of structural damage or 
failure. 
(3) Thwt or power limits will define the 
ability of the airplane to turn at constant 
altitude. The limiting condition would al- 
low increased load factor and induced drag 
until the drag equals the maximum thrust 
available from the powerplant. Such a case 
would produce the maximum turning capa- 
bility for maintaining constant altitude. 
The first illustration of figure 2.30 shows 
how the aerodynamic and structural limits 
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