Ground Reference Maneuvers
Ground reference maneuvers are part of the private pilot curriculum to teach you how to control the airplane in varying wind conditions with respect to a reference on the ground. It's actually a surprisingly commonly used skill... every time you enter an airport traffic pattern, find your house, or look at your town from the air, you're using ground reference maneuvers.
To properly perform ground reference maneuvers you must apply proper wind correction techniques, develop skills in dividing attention inside and outside the cockpit, and fine-tune the motor skills necessary to control the airplane.
Below you will find the various types of ground reference maneuvers in the ACS.
Turns Around a Point
- Select an altitude of 600-1000 AGL. I like 1000 AGL because it's easy to remember and what you do most often in traffic patterns.
- Enter downwind so that your first turn will be the maximum bank angle. Should be no more than 45° of bank
- Pick an entry point about 1/2 mile to the right of your point (assuming you sit in the left seat)
- As you turn, try to maintain a constant radius around the entire circle
- If you begin to drift away from the point, turn towards it until the point is just ahead of the left wing. Hold that until you are back to the original distance from the point.
- If you begin to drift into the point, turn so that the point falls behind your wing a little
Common Mistakes
- Failure to clear area
- Failure to establish appropriate bank on entry
- Failure to recognize wind drift
- Excessive and/or inadequate wind correction angle on downwind side or circle resulting in drift towards reference point
- Excessive and/or inadequate wind correction angle on upwind side of circle resulting in draft away from ref point
- Lack of coordination in turns
- Gaining or losing altitude
Rectangular Course
- Select an altitude of 600-1000 AGL. I like 1000 AGL.
- Enter downwind so that your first turn will be the maximum bank angle. Should be no more than 45° of bank
- Maintain a ground track (not heading) that is rectangular. The best place to see this is in your airport traffic pattern.
- Recognize whether you are drifting toward or away from the line across from you and crab the airplane into the wind to correct for it
- When turning from downwind, you turn will be steeper and will be more than a 90° turn
Common Mistakes
- Failure to clear area
- Failure to establish appropriate bank on entry
- Failure to recognize wind drift
- Excessive and/or inadequate wind correction angle on downwind side or circle resulting in drift towards reference point
- Excessive and/or inadequate wind correction angle on upwind side of circle resulting in draft away from reference point
- Lack of coordination in turns
- Gaining or losing altitude
S-Turns Across a Road
- Select an altitude of 600-1000 AGL. I like 1000 AGL.
- Enter downwind so that your first turn will be the maximum bank angle. Should be no more than 40° of bank
- As you turn, try to maintain a constant radius of the semi-circle by making appropriate wind corrections as per the image above
- Cross wings level across the road for approximately 3 seconds
Common Mistakes
- Failure to clear area
- Failure to establish appropriate bank on entry
- Failure to recognize wind drift
- Failure to select a site with a suitable emergency landing spot
- Excessive and/or inadequate wind correction angle on downwind side or circle resulting in drift towards reference point
- Excessive and/or inadequate wind correction angle on upwind side of circle resulting in draft away from reference point
- Lack of coordination in turns
- Gaining or losing altitude
ACS Test Objectives
The pilot exhibits ability to fly the ground reference maneuvers with a goal of meeting the following ACS requirements:
- Turns around a point - constant radius cirlce, +/- 100 ft, +/- 10 kts
- Rectangular course - proper wind correction, +/- 100 ft, +/- 10 kts
- S-turns across a road - constant radius semi-circles, +/- 100 ft, +/- 10 kts