Common Glider Concepts Terminology Converting Metric Distance to Feet 1 meter = 3.2808 feet 1 nautical mile (NM) = 1.852 kilometers (km) 1 nautical mile (NM) = 1.151 statute miles (SM) 1 km = 0.53996 NM 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: A glider pilot must also be able to convert distance in meters  to distance in feet, using the following conversion: 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). 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.  1-6