Private Pilot Flight Training and Instruction
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Spiral Descents
This particular maneuver is the most difficult of the ground
reference maneuvers. It requires that the student descend over
a selected point, such as the approach end of a runway, The angle
of bank will be constantly changing to adapt to the wind. The
airspeed must be constant. If the spiral is made too tight the
banks become so steep that the student can't control the airspeed.
Just pulling back to reduce airspeed has the effect of increasing
the bank angle and tightening the spiral. This is an interesting
maneuver to do in both left and right turns to show the student
why the left turns are more desirable.
This maneuver and its requirements can best be demonstrated in
an aircraft equipped with an ADF. Tune to a radio station of NDB
in a non-congested area.
Arrive at an altitude of several thousand feet over a radio station.
Reduce power and initiate a descent at best glide speed. Turn
the aircraft so that the ADF needle is pointed to the 270 bearing
to the station. The spiral descent is made in left turns in such
a manner as to keep the needle of the ADF on or near the 270 bearing.
This gives a reference for the student and instructor to gauge
the accuracy of the spiral over the point. Errors show up immediately.
The second descent should be done in right turns with the ADF
on the 090 bearing. Climbs could be made in square patterns so
as to demonstrate the movement of the ADF needle from the front
45 degree position to the rear 45 degree position at the corners
of the square. This is a excellent learning technique for demonstrating
the wind effect and the required flight corrections.
On completion of the above ground reference maneuvers the student
is advised that he should expect and be prepared for 'emergencies'
on any subsequent flight. The student should be advised that when
soloed he will be allowed and expected to practice the ground
reference maneuvers but never emergencies or off airport landings.
The limits of the practice area, the practice altitudes and any
radio procedures and assigned. We are now ready to put the skills
learned in ground reference to work. About this time the student
should realize that he has been practicing the skills needed for
takeoff and landings from the very beginning.
Should you be flying an aircraft equipped with an ADF, it is
rather interesting to perform the spiral about a radio station
antenna. Tune the ADF to the radio station, switch to ADF and
try to perform both
turns and spiral that keep the ADF needle on your wingtip. Not
easy but 'do-able'.
Written by Gene Whitt
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