|CHAPTER 9. Ground Reference Maneuvers
Turns Around a Point
Turns around a point, as a training maneuver, is a logical extension of the principles involved in the performance of S-turns across a road. The objectives are to:
In turns around a point, the aircraft is fl own in two or more complete circles of uniform radii or distance from a prominent ground reference point using a maximum bank of approximately 45° while maintaining a constant altitude.
The factors and principles of drift correction that are involved in S-turns are also applicable in this maneuver. As in other ground track maneuvers, a constant radius around a point requires a constantly changing angle of bank and angles of wind correction if any wind exists. The closer the aircraft is to a direct downwind heading where the groundspeed is greatest, the steeper the bank and the faster the rate of turn required to establish the proper wind correction angle. The more nearly it is to a direct upwind heading where the groundspeed is least, the shallower the bank and the slower the rate of turn required to establish the proper wind correction angle. Throughout the maneuver, the bank and rate of turn must be varied gradually in proportion to the groundspeed.
The point selected for turns around a point should be prominent, easily distinguished by the pilot, and yet small enough to present precise reference. [Figures 9-10 through 9-12] Isolated trees, crossroads, or other similar small landmarks are usually suitable. Right and left hand turns about a point should be practiced to develop technique in both directions. The example used here is right hand turns.
To enter turns around a point, the aircraft should be fl own on a downwind heading to one side of the selected point at a distance equal to the desired radius of turn. When any signifi cant wind exists, it will be necessary to roll into the initial bank at a rapid rate so that the steepest bank is attained abeam of the point when the aircraft is headed directly downwind. By entering the maneuver while heading directly downwind, the steepest bank can be attained immediately. Thus, if a maximum bank of 45° is desired, the initial bank is 45° if the aircraft is at the correct distance from the point. Thereafter, the bank is shallowed gradually until the point is reached at which the aircraft is headed directly upwind. At this point, the bank should be gradually steepened until the steepest bank is again attained when heading downwind at the initial point of entry.
Just as S-turns require that the aircraft be turned into the wind in addition to varying the bank, so do turns around a point. During the downwind half of the circle, the aircraft’s nose is progressively turned toward the inside of the circle; during the upwind half, the nose is progressively turned toward the outside. The downwind half of the turn around the point may be compared to the downwind side of the S-turn across a road; the upwind half of the turn around a point may be compared to the upwind side of the S-turn across a road.
As the pilot becomes experienced in performing turns around a point and has a good understanding of the effects of wind drift and varying the bank angle and wind correction angle as required, entry into the maneuver may be from any point. When entering the maneuver at a point other than downwind, however, the radius of the turn should be carefully selected. Be sure to take into account the wind velocity and groundspeed so that an excessive bank is not required later on to maintain the proper ground track. The fl ight instructor should place particular emphasis on the effect of an incorrect initial bank.
Common errors in the performance of turns around a point are:
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