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Teaching Ground Reference

More often than not ground reference is taught as though it were the end itself and not a tool for use. We are not trying to teach how to buzz your friend's front yard. The purpose of ground reference training is to be able to control the aircraft in coordinated flight while dividing attention between aircraft control, altitude, and the ground track. The application of ground reference skills and perceptions enable the pilot to safely maneuver and fly a selected ground track while landing. The key to landing is getting the aircraft configured, keeping visual track with both headings and reference points, while making wind corrections. Being able to fly an accurate ground track and altitude about an airport in a strong wind is an essential skill.

Due to wind, where the nose of the airplane points is not, necessarily, where it goes. When wind velocities permit a demonstration of how an airplane is moved by the wind can be done by holding a 360° turn in a 30° bank and noting that you do not make a circle over the ground but are moved by the wind into an ellipse. Banks used during ground reference are not all or nothing. Banks should be smoothly and continuously entered and removed. Aileron pressure must continuously be both held into the bank or against the bank any time it leaves 30-degrees. Coordinated rudder either in anticipation or application is a must. As the lessons proceed we will devote ever more attention outside the aircraft. Rectangles require about a 50-50 split. S-turns about 80-20. Eights on pylons for the commercial require near total outside attention.

When you make a turn that is going to be affected by the wind, and they all are, you are going to vary your roll rate and bank angle. How fast and how much takes practice. This practice is best noted close to the ground.
Since entries are usually with the wind behind you, you must be quicker into the bank and perhaps with greater angle. Ground track is determined by ground speed and you have the wind adding to your airspeed. You must get around further and faster, hence you begin sooner, react more quickly and bank more. Failure to do so will bend your path around the turn and require additional corrections further on.

When you are making your turn into a headwind you will again vary your roll rate and bank angle. This time you will begin later, react more slowly, and use less bank angle. Because of the wind you will be flying with a lower ground speed so everything happens more slowly.

Ground proximity flying creates problems more psychological than real. All aircraft controls function the same but the ground movement gives an impression of speed not available at altitude. This impression is sometimes a deceptive illusion. One real hazard is a bird. At ground reference altitudes the possibility of a bird strike is greatly increased. The pilot should become aware of the seasonal migratory flight of birds and of their presence. A bird instinctively reacts to an airplane as a 'hawk'. It will dive. The pilot's best reaction is to climb in the presence of birds. A defense is to fly with the landing light on. Birds will react to the light before reacting to the airplane. There is no practical need to do any ground reference below 300' and during duck hunting season 500' should be a minimum. 700' is a good student minimum. There will be little benefit if ground reference is practiced at altitudes over 1000'.

I suggest that all ground reference maneuvers be performed in a C-150 at full cruise. This reduces the potential for an inadvertent stall. The student must be told of any local obstructions such as poles or wires. A minimum altitude should be assigned for solo practice. Simulated emergencies or landings should never be attempted or practiced by the solo student. However, the student should be made aware of every potential safe landing space in the practice area in case of an actual emergency. Simulated emergencies should be experienced during ground reference training.

The student must learn to look for and find wind direction and velocity indicators. Waves, smoke, tractor dust, windmills, even the way heard animals face can be indicative of wind direction. Wind becomes a variable factor which must be anticipated and estimated to secure a desired ground track. Wind strength normally varies with altitude, becoming less as altitude decreases. Turbulence, if encountered, should be introduced gradually both as to duration and violence.

The FAR's relative to low level operations and altitudes are covered. Requirements are 500' clear of any person or residence and always able to make a safe landing without injury to persons or property. The last part of the FAR makes possible simulated emergencies from ground reference altitudes as long as a safe landing area is available. With the mastery of the 'go around' the student is ready for the low level situations that utilize that particular skill.

An area with curved roads, rectangles, and straight lines that is further away may be more effective for teaching. There are many skills to teach during enroute flying. The instructor must know about any obstructions, wires or other hazards. It is seldom possible to find exactly the size and shape pattern required. Be prepared to adapt. The instructor should have several different practice areas. This is because on a given day you want to have the best possible wind direction for doing the patterns. Calm morning winds are best for the introductory ground reference flight but the stronger afternoon winds are best for student pilot recognition of the wind effects.

The only real difference between ground reference and other flying is the difference, caused by wind, between your ground track and your heading is more apparent. In a wind your groundspeed and track will result from the sum of the vectors with respect to the ground. First, you must determine the wind using whatever ground source is available. Second, you must make a decision as to how much "wind correction" you will apply. Third, you compare your ground track with the one you want. Fourth, you make a series of changes in one and two, to get the three you want. Finding the "drift" is a matter of training your eye to differentiate between where you are heading and where you are going.

Written by Gene Whitt

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