Thursday, February 5, 2009

Lift-Off - Takeoffs And Departure Climbs

Since a good takeoff depends on the proper takeoff
attitude, it is important to know how this attitude
appears and how it is attained. The ideal takeoff attitude requires only minimum pitch adjustments
shortly after the airplane lifts off to attain the speed
for the best rate of climb (VY). Initial roll and takeoff attitude.
The pitch
attitude necessary for the airplane to accelerate to VY
speed should be demonstrated by the instructor and
memorized by the student. Initially, the student pilot
may have a tendency to hold excessive back-elevator
pressure just after lift-off, resulting in an abrupt pitch-
up. The flight instructor should be prepared for this.

Each type of airplane has a best pitch attitude for
normal lift-off; however, varying conditions may
make a difference in the required takeoff technique.
A rough field, a smooth field, a hard surface runway,
or a short or soft, muddy field, all call for a slightly

different technique, as will smooth air in contrast to
a strong, gusty wind. The different techniques for
those other-than-normal conditions are discussed
later in this chapter.

When all the flight controls become effective during
the takeoff roll in a nosewheel-type airplane, back-
elevator pressure should be gradually applied to
raise the nosewheel slightly off the runway, thus
establishing the takeoff or lift-off attitude. This is
often referred to as "rotating." At this point, the
position of the nose in relation to the horizon should
be noted, then back-elevator pressure applied as
necessary to hold this attitude. The wings must be
kept level by applying aileron pressure as necessary.

The airplane is allowed to fly off the ground while in
the normal takeoff attitude. Forcing it into the air by
applying excessive back-elevator pressure would only
result in an excessively high pitch attitude and may
delay the takeoff. As discussed earlier, excessive and
rapid changes in pitch attitude result in proportionate
changes in the effects of torque, thus making the airplane more difficult to control.

Although the airplane can be forced into the air, this is
considered an unsafe practice and should be avoided
under normal circumstances. If the airplane is forced
to leave the ground by using too much back-elevator
pressure before adequate flying speed is attained, the
wing's angle of attack may be excessive, causing the
airplane to settle back to the runway or even to stall.
On the other hand, if sufficient back-elevator pressure
is not held to maintain the correct takeoff attitude after
becoming airborne, or the nose is allowed to lower
excessively, the airplane may also settle back to the
runway. This would occur because the angle of attack
is decreased and lift diminished to the degree where it
will not support the airplane. It is important, then, to
hold the correct attitude constant after rotation or liftoff.

As the airplane leaves the ground, the pilot must
continue to be concerned with maintaining the
wings in a level attitude, as well as holding the
proper pitch attitude. Outside visual scan to
attain/maintain proper airplane pitch and bank attitude must be intensified at this critical point. The
flight controls have not yet become fully effective,
and the beginning pilot will often have a tendency
to fixate on the airplane's pitch attitude and/or the
airspeed indicator and neglect the natural tendency
of the airplane to roll just after breaking ground.

During takeoffs in a strong, gusty wind, it is advisable
that an extra margin of speed be obtained before the
airplane is allowed to leave the ground. A takeoff at the
normal takeoff speed may result in a lack of positive

control, or a stall, when the airplane encounters a
sudden lull in strong, gusty wind, or other turbulent
air currents. In this case, the pilot should allow the
airplane to stay on the ground longer to attain more
speed; then make a smooth, positive rotation to leave
the ground.

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