Seven ways Private Pilot Ground Reference Maneuvers can go awry and what to do about them.
Ground reference maneuvers teach pilots to control their aircraft’s path along the ground in various wind conditions. Traffic patterns, approaches, takeoffs, and landings all require pilots to precisely control their ground track. During Private Pilot training student pilots mainly learn and practice three ground reference maneuvers: rectangular course, turns around a point, and s-turns across a road. Here are some common errors in Private Pilot ground reference maneuvers and their tips to correct them.
Improper Entry Procedure
Ensure that you start each ground reference maneuver at the appropriate altitude and airspeed: 600 to 1000 feet above ground level (AGL) at or below maneuvering speed. Be sure the area above, below, and around the aircraft is free of hazards. Towers and other obstructions are of particular concern given the low altitude of ground reference maneuvers. You need to be at least 500’ above any obstruction within 2000’ horizontally of the aircraft. Establish your altitude and clear the area before entering the maneuver.
The specific entry procedure depends on the maneuver being performed:
- Rectangular Course – Enter at a 45 degree angle to the downwind leg – the same way you’d enter a traffic pattern.
- Turns Around a Point – Enter downwind at an appropriate distance from the reference point. Close enough that distance and wind drift are easy to determine, but not so close that banks over 45° are needed.
- S-Turns Across a Road – Enter downwind crossing the road/reference line perpendicular to it.
Poor Planning, Orientation, or Division of Attention
These errors fall under “situational awareness.” Give yourself enough room to fly the proper entry for each maneuver and choose reference points or lines that permit enough room to complete the entire maneuver. Keep track of your progress through each maneuver, the direction you started in, and the direction in which the maneuver will be complete. Don’t perform only ¾ of a turn around a point or three legs of the rectangular course and think that you’re done. While flying each maneuver ensure you are also maintaining altitude, airspeed, proper coordination, and you are keeping an eye out for obstructions, other airplanes, and other hazards. Don’t focus so much on the maneuver that you neglect of these other tasks.
During all these maneuvers, proper coordination of the flight controls is essential. Many fatal stall/spin accidents happen during poorly coordinated turns in the traffic pattern. Since ground reference maneuvers are in large part training for the traffic pattern, proper coordination should be a central theme of the maneuver. Here are specific areas where coordination may go awry:
- The entry to S-turns and Turns around a point requires a rapid roll-in. The pilot rolls quickly from wings level to the steepest bank of the maneuver. Apply rudder to correct for the adverse yaw produced during the roll.
- During any turn where the required bank angle exceeds pilot expectations, it may be tempting to use less bank and attempt to skid the airplane around the turn with excess rudder. Stay coordinated.
- While turning to align with a straight section of rectangular course it’s tempting to cheat with rudder. This may be to compensate for a late or early turn. Remain coordinated and adjust your alignment by varying bank in the turn, or your crab angle on the straight-away.
Poor Wind Drift Correction
One of the primary functions of ground reference maneuvers is to learn and practice the ability to control wind drift in flight. Drift correction errors typically come in a few varieties:
- Crab Angle – In straight-and-level flight, the method of wind drift control is flying at a crab angle. Control the angle based on the effect of the wind. For each straight-and-level segment, note any drift and correct accordingly.
- Anticipating Turn Amount – The crab angle needed on each leg of the rectangular course is different. As a result, the heading change required to turn from one leg to the next could be substantially more or less than 90 degrees. This requires starting the turn at the appropriate moment and rolling out with the crab established.
- Faulty Start of Turn – The quick roll at the start of turns around a point and s-turns across a road goes from wings level to the steepest bank angle of the maneuver. This roll into the maneuvers has to be timed well.
- Bank Angle – We control ground track in a turn by varying our bank angle. Don’t be shy about varying the bank angle as needed.
Unsymmetrical S-Turns Ground Track
Each “half” of an S-turn across a road should be equal in size and equal but opposite shape to its counterpart. Imagine the first turn tracks a semicircle on the ground of about a ¼ mile radius. The next turn should trace the same size semi-circle on the other side of the road. Begin each turn with the same bank angle (but opposite direction) that you finished the previous turn. The bank angle at the end of the second turn should be the same as the bank at the start of the first.
Each semi-circle should begin and end with the airplane crossing perpendicular to the road. Cross the road just as you complete one turn and begin to roll into the next. Pay attention to crossing the road before you complete the turn or finishing the turn long before crossing the road. These indicate a need to improve timing of bank angle changes.
Altitude and Airspeed Deviations
The Private Pilot ACS ground reference maneuver tolerances for altitude and airspeed are +/- 100ft and +/- 10 knots respectively. The major contributor to altitude and airspeed deviations is losing awareness of your pitch attitude. Performing turns while your attention is focused on points on the ground contributes to this. As you bank you will need to increase back pressure slightly to maintain your altitude. Excess back pressure resulting in pitch increases and climbs during turns are also common. Loss of airspeed can occur during any turn especially at steeper bank angles. Adjust power as needed.
Lack of Suitable Emergency Landing Area
Being low to the ground provides fewer options in the event of an engine failure or other emergency. Have suitable landing sites available when performing ground reference maneuvers and ensure they remain within gliding distance. It’s a good idea to identify and brief your emergency landing field prior to starting the maneuver.
Ground Reference Maneuvers are a vital part of learning to fly and great preparation for pattern work. For more information on these maneuvers see the FAA’s Airplane Flying Handbook. What errors have you seen during these maneuvers? Got any tips or suggestions, let me know in the comments below!
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