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wing and the speed of the outside wing. The wing on
the outside of the turn travels a longer circuit than the
inside wing, yet both complete their respective circuits
in the same length of time. Therefore, the outside wing
travels faster than the inside wing, and as a result, it
develops more lift. This creates an overbanking tendency
that must be controlled by the use of the ailerons.
Because the outboard wing is developing more lift, it
also has more induced drag. This causes a slip during
steep turns that must be corrected by rudder usage.
To establish the desired angle of bank, the pilot should
use visual reference points on the glider, the Earth's
surface, and the natural horizon. The pilot's posture
while seated in the glider is very important, particularly
during turns. It will affect the interpretation of
outside visual references. The beginning pilot may lean
away from or into the turn rather than ride with the
glider. This should be corrected immediately if the
pilot is to properly learn to use visual references.
Applications of large aileron and rudder produces
rapid roll rates and allow little time for corrections
before the desired bank is reached. Slower (small control
displacement) roll rates provide more time to make
necessary pitch and bank corrections. As soon as the
glider rolls from the wings-level attitude, the nose will
start to move along the horizon, increasing its rate of
travel proportionately as the bank is increased.
COMMON ERRORS
• Failure to clear turn.
• Nose starts to move before the bank starts—
rudder is being applied too soon.
• Bank starts before the nose starts turning, or
the nose moves in the opposite direction—the
rudder is being applied too late.
• Nose moves up or down when entering a
bank—excessive or insufficient elevator is
being applied.
As the desired angle of bank is established, aileron and
rudder pressures should be relaxed. This stops the bank
from increasing because the aileron and rudder control
surfaces will be neutral in their streamlined position.
The up-elevator pressure should not be relaxed, but
should be held constant to maintain the desired airspeed.
Throughout the turn, the pilot should crosscheck
the airspeed indicator to verify the proper pitch is being
maintained. The crosscheck should also include outside
visual references. If gaining or losing airspeed, the pitch
attitude should be adjusted in relation to the horizon.
During all turns, the ailerons, rudder, and elevator are
used to correct minor variations in pitch and bank just
as they are in straight glides.
The roll-out from a turn is similar to the roll-in except
the flight controls are applied in the opposite direction.
Aileron and rudder are applied in the direction of the
roll-out or toward the high wing. As the angle of bank
decreases, the elevator pressure should be relaxed, as
necessary, to maintain airspeed.
Since the glider will continue turning as long as there is
any bank, the roll-out must be started before reaching
the desired heading. The amount of lead required to
roll-out on the desired heading depends on the degree
of bank used in the turn. Normally, the lead is one half
the degrees of bank. For example, if the bank is 30°,
lead the roll-out by 15°. As the wings become level, the
control pressures should be smoothly relaxed so the
controls are neutralized as the glider returns to straight
flight. As the roll-out is being completed, attention
should be given to outside visual references, as well as
the airspeed and heading indicators to determine that
the wings are being leveled and the turn stopped.
COMMON ERRORS
• Rough or uncoordinated use of controls
during the roll-in and roll-out.
• Failure to establish and maintain the desired
angle of bank.
• Overshooting/undershooting the desired
heading.
In a slipping turn, the glider is not turning at the rate
appropriate to the bank being used, since the glider is
yawed toward the outside of the turning flight path.
The glider is banked too much for the rate of turn, so
the horizontal lift component is greater than the centrifugal
force. Equilibrium between the horizontal lift
component and centrifugal force is reestablished either
by decreasing the bank (ailerons), increasing yaw
(rudder), or a combination of the two. [Figure 7-26]
7-25
A skidding turn results from an excess of centrifugal
force over the horizontal lift component, pulling the
glider toward the outside of the turn. The rate of turn is
　
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本文鏈接地址：Glider Flying Handbook(72)