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aircraft, the results of control pressures on the action, and
attitude of the aircraft.
As soon as the pilot shows profi ciency in the fundamental
maneuvers, it is necessary that he or she be introduced to
ground reference maneuvers requiring attention beyond
practical application and current knowledge base.
It should be stressed that during ground reference maneuvers,
it is equally important that previously learned basic fl ying
technique be maintained. The fl ight instructor should not allow
any relaxation of the student’s previous standard of technique
simply because a new factor is added. This requirement
should be maintained throughout the student’s progress from
maneuver to maneuver. Each new maneuver should embody
some advanced knowledge and include principles of the
preceding maneuver in order to maintain continuity. Each
new skill introduced should build on one already learned so
that orderly, consistent progress can be made.
Maneuvering by Reference to Ground
Objects
Ground track or ground reference maneuvers are performed at
relatively low altitudes while applying wind drift correction
as needed to follow a predetermined track or path over the
ground. These maneuvers are designed to develop the ability
to control the aircraft and to recognize and correct for the
effect of wind, while dividing attention among other matters.
This requires planning ahead of the aircraft, maintaining
orientation in relation to ground objects, fl ying appropriate
headings to follow a desired ground track, and being
cognizant of other air traffi c in the immediate vicinity.
Ground reference maneuvers should be fl own at an altitude of
approximately 500 to 1,000 feet above ground level (AGL).
The actual altitude will depend on the ability to reach a safe
landing area if there is an engine failure during the maneuver
and the type of air in which the maneuvers are being fl own.
If there is signifi cant vertical movement of the air, higher
altitudes should be used to avoid the possibility of fl ying
below 400 feet AGL, the minimum altitude recommended
in the Practical Test Standards (PTS).
Overall, the following factors should be considered in
determining the appropriate altitudes for ground reference
maneuvers:
• The speed with relation to the ground should not be
so apparent that events happen too rapidly.
• The radius of the turn and the path of the aircraft over
the ground should be easily noted and changes planned
and effected as circumstances require.
• Drift should be easily discernable but should not
overtax the student in making corrections.
• Objects on the ground should appear in their proportion
and size.
• The altitude should be low enough to render any gain
or loss apparent to the student, but not recommended
lower than 400 feet above the highest obstruction
and in no case lower than 500 feet above any person,
vessel, vehicle, or structure.
During these maneuvers, both the instructor and the student
should be alert for available forced-landing fi elds. The
area chosen should be away from communities, livestock,
or groups of people to prevent becoming an annoyance or
hazard. Due to the altitudes at which these maneuvers are
performed, there is little time available to search for a suitable
fi eld for landing in the event the need arises.
Drift and Ground Track Control
Whenever an object is free from the ground, it is affected
by the medium surrounding it. This means that a free object
moves in whatever direction and speed that the medium
moves.
For example, if a powerboat were crossing a still river, the
boat could head directly to a point on the opposite shore
and travel on a straight course to that point without drifting.
However, if the river were fl owing swiftly, the water current
would require consideration. That is, as the boat progresses
forward on its own power, it must also move upstream at
the same rate the river is moving it downstream. This is
accomplished by angling the boat upstream suffi ciently to
counteract the downstream fl ow. If this is done, the boat
follows the desired track across the river from the departure
point directly to the intended destination point. If the boat
is not headed suffi ciently upstream, it would drift with the
current and run aground at some point downstream on the
opposite bank. [Figure 9-1]
As soon as an aircraft becomes airborne, it is free of ground
friction. Its path is then affected by the air mass in which it is
fl ying; therefore, the aircraft (like the boat) does not always
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Weight-Shift Control Aircraft Flying Handbook(102)
