Approach and Landing
A normal approach and landing involves the use of procedures
for what is considered a normal situation; that is, when engine
power is available, the wind is light, or the final approach is
made directly into the wind, the final approach path has no
obstacles and the landing surface is firm and of ample length
to gradually bring the airplane to a stop. The selected landing
point is normally beyond the runway’s approach threshold
but within the first 1/3 portion of the runway.
The factors involved and the procedures described for the
normal approach and landing also have applications to the
other-than-normal approaches and landings and are discussed
later in this chapter. This being the case, the principles of
normal operations are explained first and must be understood
before proceeding to the more complex operations. To help
the pilot better understand the factors that influence judgment
and procedures, the last part of the approach pattern and the
actual landing is divided into five phases:
Base Leg
The placement of the base leg is one of the more important
judgments made by the pilot in any landing approach.
The pilot must accurately judge the altitude
and distance from which a gradual, stabilized descent results
in landing at the desired spot. The distance depends on the
altitude of the base leg, the effect of wind, and the amount
of wing flaps used. When there is a strong wind on final
approach or the flaps are used to produce a steep angle
of descent, the base leg must be positioned closer to the
approach end of the runway than would be required with a
light wind or no flaps. Normally, the landing gear is extended
and the before-landing check completed prior to reaching
the base leg.
Final Approach
After the base-to-final approach turn is completed, the
longitudinal axis of the airplane is aligned with the centerline
of the runway or landing surface so that drift (if any) is
recognized immediately. On a normal approach, with no
wind drift, the longitudinal axis is kept aligned with the
runway centerline throughout the approach and landing. (The
proper way to correct for a crosswind is explained under the
section, Crosswind Approach and Landing. For now, only
an approach and landing where the wind is straight down the
runway are discussed.)
A stabilized descent angle is controlled throughout the
approach so that the airplane lands in the center of the first
third of the runway. The descent angle is affected by all four
fundamental forces that act on an airplane (lift, drag, thrust,
and weight). If all the forces are constant, the descent angle
is constant in a no-wind condition. The pilot controls these
forces by adjusting the airspeed, attitude, power, and drag
(flaps or forward slip). The wind also plays a prominent part
in the gliding distance over the ground; the
pilot does not have control over the wind but corrects for
its effect on the airplane’s descent by appropriate pitch and
power adjustments.
Round Out (Flare)
The round out is a slow, smooth transition from a normal
approach attitude to a landing attitude, gradually rounding
out the flightpath to one that is parallel with, and within a
very few inches above, the runway. When the airplane, in a
normal descent, approaches within what appears to be 10 to
20 feet above the ground, the round out or flare is started.
This is a continuous process until the airplane touches down
on the ground.
As the airplane reaches a height above the ground where a
change into the proper landing attitude can be made, back-
elevator pressure is gradually applied to slowly increase the
pitch attitude and angle of attack (AOA).
This causes the airplane’s nose to gradually rise toward the desired
landing attitude. The AOA is increased at a rate that allows the
airplane to continue settling slowly as forward speed decreases.
When the AOA is increased, the lift is momentarily increased
and this decreases the rate of descent. Since power normally
is reduced to idle during the round out, the airspeed also
gradually decreases. This causes lift to decrease again and
necessitates raising the nose and further increasing the AOA.
During the round out, the airspeed is decreased to touchdown
speed while the lift is controlled so the airplane settles gently
onto the landing surface. The round out is executed at a rate
that the proper landing attitude and the proper touchdown
airspeed are attained simultaneously just as the wheels
contact the landing surface.
Touchdown
The touchdown is the gentle settling of the airplane onto the
landing surface. The round out and touchdown are normally
made with the engine idling and the airplane at minimum
controllable airspeed so that the airplane touches down on
the main gear at approximately stalling speed. As the airplane
settles, the proper landing attitude is attained by application
of whatever back-elevator pressure is necessary.
Some pilots try to force or fly the airplane onto the ground
without establishing the proper landing attitude. The airplane
should never be flown on the runway with excessive speed.
A common technique to making a smooth touchdown is to
actually focus on holding the wheels of the aircraft a few
inches off the ground as long as possible using the elevators
while the power is smoothly reduced to idle. In most cases,
when the wheels are within 2 or 3 feet off the ground, the
airplane is still settling too fast for a gentle touchdown;
therefore, this descent must be retarded by increasing back-
elevator pressure. Since the airplane is already close to
its stalling speed and is settling, this added back-elevator
pressure only slows the settling instead of stopping it. At
the same time, it results in the airplane touching the ground
in the proper landing attitude and the main wheels touching
down first so that little or no weight is on the nose wheel.
After-Landing Roll
The landing process must never be considered complete until
the airplane decelerates to the normal taxi speed during the
landing roll or has been brought to a complete stop when clear
of the landing area. Numerous accidents occur as a result
of pilots abandoning their vigilance and failing to maintain
positive control after getting the airplane on the ground.
A pilot must be alert for directional control difficulties
immediately upon and after touchdown due to the ground
friction on the wheels. Loss of directional control may lead
to an aggravated, uncontrolled, tight turn on the ground, or
a ground loop. The combination of centrifugal force acting
on the center of gravity (CG) and ground friction of the
main wheels resisting it during the ground loop may cause
the airplane to tip or lean enough for the outside wingtip to
contact the ground. This imposes a sideward force that could
collapse the landing gear.
The rudder serves the same purpose on the ground as it
does in the air—it controls the yawing of the airplane. The
effectiveness of the rudder is dependent on the airflow, which
depends on the speed of the airplane. As the speed decreases
and the nose wheel has been lowered to the ground, the
steerable nose provides more positive directional control.
The brakes of an airplane serve the same primary purpose as
the brakes of an automobile—to reduce speed on the ground.
In airplanes, they are also used as an aid in directional control
when more positive control is required than could be obtained
with rudder or nose wheel steering alone.
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