曝光台 注意防骗
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to counteract wind drift in turns.
• Failure to anticipate needed drift correction.
• Failure to apply needed drift correction in a
timely manner.
• Failure to roll out of turns on proper heading.
• Inability to divide attention between reference
points on the ground, airplane control, and scanning
for other aircraft.
EIGHTS-ON-PYLONS (PYLON EIGHTS)
The pylon eight is the most advanced and most difficult
of the low altitude flight training maneuvers.
Because of the various techniques involved, the pylon
eight is unsurpassed for teaching, developing, and testing
subconscious control of the airplane.
As the pylon eight is essentially an advanced
maneuver in which the pilot’s attention is directed
at maintaining a pivotal position on a selected pylon,
with a minimum of attention within the cockpit, it
should not be introduced until the instructor is assured
that the student has a complete grasp of the fundamentals.
Thus, the prerequisites are the ability to make a coordinated
turn without gain or loss of altitude, excellent feel of
the airplane, stall recognition, relaxation with low altitude
maneuvering, and an absence of the error of over
concentration.
Like eights around pylons, this training maneuver also
involves flying the airplane in circular paths, alternately
left and right, in the form of a figure 8 around
two selected points or pylons on the ground. Unlike
eights around pylons, however, no attempt is made to
maintain a uniform distance from the pylon. In eightson-
pylons, the distance from the pylons varies if there
is any wind. Instead, the airplane is flown at such a
precise altitude and airspeed that a line parallel to the
airplane’s lateral axis, and extending from the pilot’s
eye, appears to pivot on each of the pylons. [Figure 6-
10] Also, unlike eights around pylons, in the performance
of eights-on-pylons the degree of bank increases
as the distance from the pylon decreases.
The altitude that is appropriate for the airplane being
flown is called the pivotal altitude and is governed by
the groundspeed. While not truly a ground track
maneuver as were the preceding maneuvers, the objective
is similar—to develop the ability to maneuver the
airplane accurately while dividing one’s attention
between the flightpath and the selected points on the
ground.
In explaining the performance of eights-on-pylons, the
term “wingtip” is frequently considered as being synonymous
with the proper reference line, or pivot
point on the airplane. This interpretation is not
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always correct. High-wing, low-wing, sweptwing, and
tapered wing airplanes, as well as those with tandem or
side-by-side seating, will all present different angles from
the pilot’s eye to the wingtip. [Figure 6-11] Therefore, in
the correct performance of eights-on-pylons, as in other
maneuvers requiring a lateral reference, the pilot should
use a sighting reference line that, from eye level, parallels
the lateral axis of the airplane.
Closest to
the Pylon
Lowest
Groundspeed
Lowest Pivotal
Altitude
High Groundspeed
High Pivotal Altitude
Entry
Figure 6-10. Eights-on-pylons.
Figure 6-11. Line of sight.
Lateral Axis
Line of Sight
Lateral Axis
Line of Sight
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The sighting point or line, while not necessarily on the
wingtip itself, may be positioned in relation to the
wingtip (ahead, behind, above, or below), but even
then it will differ for each pilot, and from each seat in
the airplane. This is especially true in tandem (fore and
aft) seat airplanes. In side-by-side type airplanes, there
will be very little variation in the sighting lines for different
persons if those persons are seated so that the
eyes of each are at approximately the same level.
An explanation of the pivotal altitude is also essential.
There is a specific altitude at which, when the airplane
turns at a given groundspeed, a projection of the sighting
reference line to the selected point on the ground
will appear to pivot on that point. Since different airplanes
fly at different airspeeds, the groundspeed will
be different. Therefore, each airplane will have its own
pivotal altitude. [Figure 6-12] The pivotal altitude does
not vary with the angle of bank being used unless the
bank is steep enough to affect the groundspeed. A rule
of thumb for estimating pivotal altitude in calm wind is
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AIRPLANE FLYING HANDBOOK 飞机飞行手册上(72)
