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fly a glider. For more information on the certification of the gliders themselves, refer to 14 CFR part 21, the European Aviation Safety Agency (EASA) Certification Specifications (CS) 22.221, and the Weight and Balance Handbook (FAA-H-8083-1). 

## Common Glider Concepts 

## Terminology 

There are a number of terms used in gliding that all glider pilots should be familiar with. The list is not comprehensive, but includes the following: 

• Knot—one nautical mile per hour (NMPH). A nautical mile is 6,076.115 feet as opposed to 5,280 feet in a statute mile. Rounded that is 6,000 feet, which divided by 60 minutes equals 100 feet per minute (fpm). Hence, this gives 1 on a variometer, which means one knot per hour or approximately 100 fpm. A 4-knot thermal lifts the glider at 400 fpm. 

• Lift—measured in knots, rising air lifting the glider higher. 

• Sink—falling air that forces the glider to lose height and is measured in knots. 

• Attitude—the orientation of an aircraft in the air with respect to the horizon. If the aircraft is diving, then it is said to have a “nose-down attitude about its lateral axes.” Attitude can also be a roll or bank as referenced to the longitudinal axis and pitch up or down as referenced to lateral axis. 

• Pitch—the up and down movement around the lateral axis for pitch. Increasing the pitch lifts the nose and drops the tail. Decreasing the pitch drops the nose and lifts the tail. 

• Roll—movement around a line between the nose and tail longitudinal axes. Rolling right drops the right wing while lifting the left wing. 

• Yaw—a turning motion in which the nose of the aircraft moves to the right or left about its vertical axis. 

• Cable—steel wire used to connect the glider to the winch. It is approximately 5mm wide and should be avoided at all times until after the correct training for safe handling. There are some winch operations using composite fiber cable that is stronger and lighter than steel. 

• Strop—a special part of the winch cable that is designed to be handled. The strop has the tost rings that are attached to the glider. 

• Weak link—a safety device in the winch cable or tow line. They come in various strengths (indicated by their color) and the correct one must be used with a given glider. 

• Elevator—a moveable section in the tailplane (the small wing at the back of the glider) that effectively controls whether the glider climbs or dives in flight. 

• Thermal—a bubble or column of warm rising air. Pilots try to find these columns of rising air and stay within them to gain altitude. 

## Converting Metric Distance to Feet 

A glider pilot must also be able to convert distance in meters to distance in feet, using the following conversion: 

Multiply the number of meters by 3.2808 

To convert kilometers to nautical miles and nautical miles to kilometers or statute miles, use the following: 

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