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Windsock
Segmented Circle
Traffic Pattern Indicator
(indicates location of base leg)
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7-4
safe altitude is attained, the pilot should commence a
shallow bank turn to the upwind side of the airport.
This will allow better visibility of the runway for
departing aircraft.
The departure leg of the rectangular pattern is a
straight course aligned with, and leading from, the
takeoff runway. This leg begins at the point the airplane
leaves the ground and continues until the 90°
turn onto the crosswind leg is started.
On the departure leg after takeoff, the pilot should continue
climbing straight ahead, and, if remaining in the
traffic pattern, commence a turn to the crosswind leg
beyond the departure end of the runway within 300 feet
of pattern altitude. If departing the traffic pattern, continue
straight out or exit with a 45° turn (to the left
when in a left-hand traffic pattern; to the right when in
a right-hand traffic pattern) beyond the departure end
of the runway after reaching pattern altitude.
The crosswind leg is the part of the rectangular pattern
that is horizontally perpendicular to the extended centerline
of the takeoff runway and is entered by making
approximately a 90° turn from the upwind leg. On the
crosswind leg, the airplane proceeds to the downwind
leg position.
Since in most cases the takeoff is made into the wind,
the wind will now be approximately perpendicular to
the airplane’s flightpath. As a result, the airplane will
have to be turned or headed slightly into the wind
while on the crosswind leg to maintain a ground track
that is perpendicular to the runway centerline extension.
Additional information on airport operations can be
found in the Aeronautical Information Manual (AIM).
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NORMAL 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 should be beyond the runway’s approach
threshold but within the first one-third 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
which 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. So that the pilot may better
understand the factors that will influence judgment and
procedures, that last part of the approach pattern and
the actual landing will be divided into five phases: the
base leg, the final approach, the roundout, the
touchdown, and the after-landing roll.
It must be remembered that the manufacturer’s
recommended procedures, including airplane
configuration and airspeeds, and other information
relevant to approaches and landings in a specific make
and model airplane are contained in the FAA-approved
Airplane Flight Manual and/or Pilot’s Operating
Handbook (AFM/POH) for that airplane. If any of the
information in this chapter differs from the airplane
manufacturer’s recommendations as contained in
the AFM/POH, the airplane manufacturer’s
recommendations take precedence.
BASE LEG
The placement of the base leg is one of the more
important judgments made by the pilot in any landing
approach. [Figure 8-1] The pilot must accurately judge
the altitude and distance from which a gradual descent
will result in landing at the desired spot. The distance
will depend 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 will be
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
Figure 8-1. Base leg and final approach.
8-1
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flaps. Normally, the landing gear should be extended
and the before landing check completed prior
to reaching the base leg.
After turning onto the base leg, the pilot should start
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AIRPLANE FLYING HANDBOOK 飞机飞行手册上(77)
