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The technique
used during the initial takeoff roll in a crosswind
is generally the same as the technique used
in a normal takeoff roll, except that the pilot
must apply aileron pressure into the crosswind.
This raises the aileron on the upwind wing,
imposing a downward force on the wing to counteract
the lifting force of the crosswind; and thus
preventing the wing from rising. The pilot must
remember that since the ailerons and rudder
are deflected, drag will increase; therefore,
less initial takeoff performance should be expected
until the airplane is wings-level in coordinated
flight in the climb.
While taxiing into takeoff position, it is essential
that the pilot check the windsock and other
wind direction indicators for the presence of
a crosswind. If a crosswind is present, the
pilot should apply full aileron pressure into
the wind while beginning the takeoff roll. The
pilot should maintain this control position,
as the airplane accelerates, until the ailerons
become effective in maneuvering the airplane
about its longitudinal axis. As the ailerons
become effective, the pilot will feel an increase
in pressure on the aileron control.
While holding aileron pressure into the wind,
the pilot should use the rudder to maintain
a straight takeoff path. Since the airplane
tends to weathervane into the wind while on
the ground, the pilot will typically apply downwind
rudder pressure. When the pilot increases power
for takeoff, the resulting P-factor causes the
airplane to yaw to the left. While this yaw
may be sufficient to counteract the airplane’s
tendency to weathervane into the wind in a crosswind
to the right, it may aggravate this tendency
in a
crosswind to the left. In any case, the pilot
should apply rudder pressure in the appropriate
direction to keep the airplane rolling straight
down the runway.
As the forward speed of the airplane increases,
the pilot should only apply enough aileron pressure
to keep the airplane laterally aligned with
the runway centerline. The rudders keep the
airplane pointed parallel with the runway centerline,
while the ailerons keep the airplane laterally
aligned with the centerline. The crosswind component
effect will not completely vanish; therefore,
the pilot must maintain some aileron pressure
throughout the takeoff roll to keep the crosswind
from raising the upwind wing. If the upwind
wing rises, the amount of wing surface exposed
to the crosswind will increase, which may cause
the airplane to "skip."
This “skipping” is usually indicated
by a series of very small bounces caused by
the airplane attempting to fly and then settling
back onto the runway. During these bounces,
the crosswind also tends to move the airplane
sideways, and these bounces develop into side-skipping.
This side-skipping imposes severe side stresses
on the landing gear and may result in structural
failure.
During a crosswind takeoff roll, it is important
that the pilot hold sufficient aileron pressure
into the wind not only to keep the upwind wing
from rising but to hold that wing down so that
the airplane sideslips into the wind enough
to counteract drift immediately after lift-off.
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