DescriptionUniform 180° turns in opposite directions crossing and re-crossing a straight-line reference over the ground.
ObjectiveCompensate for wind drift during a turn. As groundspeed increases, so should the angle of bank in a turn.
Procedure• Complete pre-maneuver checklist. Clear the area. Make radio calls as appropriate. Maintain 2300 RPM and approximately 90 KIAS. Note wind direction using locally reported weather stations, blowing smoke/dust, or groundspeed using the GPS.• Select suitable ground reference. Select a long and prominent straight-line reference on the ground perpendicular to the wind direction away from populated areas (ie; road, fence, or section line).• Enter downwind. Begin maneuver perpendicular to selected reference line and roll into a turn once crossing it. Downwind entry provides the highest groundspeed in the first 90° of the turn. This will be a relatively steep bank angle.• Track a half circle. Continue turn and decrease bank angle appropriately as groundspeed decreases past the 90° point to track a symmetrical half-circle.• Cross the reference line upwind. Cross the reference line after 180° turn is completed with wings level. Begin a turn in the opposite direction as soon as reference line is crossed.• Track another half circle. Complete turn in opposite direction, noting now that a shallower bank angle at the beginning of turn should increase as groundspeed increases past the 90° point.• Cross the reference line downwind. Cross the reference line after 180° turn is completed with wings level.
ACS requires this maneuver to be completed 600-1000 feet AGL.
ACS Standards• Clear the area.• Select a suitable ground reference area, line, or point as appropriate.• Plan the maneuver:• Enter perpendicular to the selected reference line, 600 to 1,000 feet AGL at an appropriate distance from the selected reference area• Apply adequate wind-drift correction during straight and turning flight to maintain a constant radius turn on each side of a selected reference line or point.• Reverse the turn directly over the selected reference line• Divide attention between airplane control, traffic avoidance and the ground track while maintaining coordinated flight.• Maintain altitude ±100 feet; maintain airspeed ±10 knots.