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Glossary of Terms
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AERODYNAMICS
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The study of the movement of a body through the air, such as a paragliding wing
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AGL
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Above Ground Level
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AIRFOIL
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A curved surface designed to generate lift moving through the air.
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AIRSPEED
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The velocity of the glider through the air
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AIRSPEED INDICATOR
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An instrument for measuring airspeed
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ALTIMETER
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An instrument for measuring altitude above a pre-determined point
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ANGLE OF ATTACK
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The angle the relative wind makes with the chord of an airfoil
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ASPECT RATIO
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Ratio of the span of the chord or spanē divided by the surface area
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ATC
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Air Traffic Control – First pilot on site to phone the local ATC and advise them of any Paragliding Activity.
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BIG EARS
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A technique to increase one's descent rate by folding in the wing
tips.
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BRAKES
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The controls of a paraglider that pull down the trailing edge
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CAA
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Civil Aviation Authority
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CAMBER
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The amount of curvature on the upper surface of an airfoil.
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CANOPY
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The material or “sail” of a paraglider that forms the airfoil or wing
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CELLS
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The individual inflated units of a canopy between suspension lines
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CENTRE OF GRAVITY
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The point along the wing where all the weight is suspended
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CHECK LIST
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A routine safety check that a pilot performs before committing to the air. For example: reserve pin, leg straps, chest straps, helmet,
radio, vario, wind, traffic.
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CHORD
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Measurement of an airfoil from the leading edge to the trailing edge.
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COORDINATED TURN
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A turn at a steady state in which a slip or a stall does not occur.
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CORE
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The centre of a thermal where the strongest lift is found. To centre a thermal.
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CROSS COUNTRY (XC)
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Flying beyond the normal landing field by using lift encountered along the way.
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CROSS-PORTS
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The holes in ribs that allow equalisation of pressure between cells.
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CROSSWIND
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A wind angling across the normal launch or flight path.
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DEEP STALL
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An emergency situation whereby a glider descends with little or no forward speed.
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DHV
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The German certification agency. Wings get a rating of DHV 1,
DHV 1
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DOWN WIND
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Flying in a direction the same as the wind ( flying with a tailwind)
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DRAG
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The energy losses on the glider due to the friction and mass or the
air.
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DYNAMIC STALL
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A stall produced by the pulling the brakes so rapidly so that the pilot swings forward and worsens the stall.
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END CELL CLOSURE
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A problem during inflation whereby the ends of the canopy do not open properly and may result in a collapse.
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FLIGHT DECK
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An inspection after inflation to check for tangled lines or end cell closures.
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GAGGLE
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A group of pilots flying together in a thermal.
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GLIDE ANGLE
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The angle between the glide path and the horizontal.
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GLIDE PATH
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The flight path of a glider
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GLIDE RATIO
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The ratio of the distance travelled forward to the distance dropped. This is usually interchangeably with L/D (Lift/Drag).
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GLIDING
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Flight that continues from an elevated point to a lower point
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GPS
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Global Positioning System
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GROUND SPEED
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The velocity of a glider over the ground. This is different from airspeed if any wind is present.
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GROSS WEIGHT
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Total weight of the glider and the heaviest allowed payload (pilot)
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HARNESS
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A suspension system that supports a pilot and attaches him to a glider.
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HEADING
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The direction a glider points (this will be different from actual flight directions in a cross wind)
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HEADWIND
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A wind from the front or opposite the heading
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HG
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Acronym for Hand Gliding
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HORSESHOE STALL
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A manoeuvre whereby full brakes are held until the canopy collapses in the form of a horseshoe.
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INFLATION
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The act of bringing a glider overhead and inflating it with air. Every good launch starts with a solid inflation.
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INVERSION
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An inversed temperature profile with altitude. The temperature rises (rather than falls) with altitude gain
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KITING
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The art of flying a paraglider while on the ground. Good kiting skills are essential for a good launch technique. A good pilot can kite for a long time without looking over
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LAPSE RATE
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The rate at which the temperature falls with altitude gain. A healthy lapse rate indicates an unstable day with good potential for soaring flights. [Top]
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LEADING EDGE
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The forward most part of the wing. The span that forms the forward part.
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LIFT
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Uprising air used by the pilot to soar. Either due to thermals, ridge (mechanical lift) or converging air masses.
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LIFT TO DRAG
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A comparison of the lift forces to the drag forces. (See glide ration)
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LOG BOOK
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A book used to list flights and achievements
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LZ
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Landing Zone
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MAXIMUM GLIDE RATIO
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The best possible glide ratio for a given pilot and glider combination
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MINIMUM SINK RATE
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The slowest descent rate possible with a given pilot and glider combination
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MSL
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Mean Sea Level - for indicating height above the average sea level
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PITCH
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Amount of nose up or nose down. Movement about a lateral axis
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POLAR CURVE
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A graph showing the performance of a wing based on its airspeed and sink rate. The tangent from the origin to the curve shows the speed for best glide. The best glide speed varies with changes in lift/sink and wind conditions (head/tail wind).
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PRE-FLIGHT CHECK
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A careful inspection of the entire flying system before inflation
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RAPID LINK (QUICK LINK) KARABINERS
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A small looped device used to attach risers to a harness
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REFLEX
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An upward bending of the rear of an airfoil to prevent dives
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RELATIVE WIND
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The wind relative to the glider in flight. Since the glider is always moving in respect of the air around it, the relative wind is different from the wind on the ground
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RIBS
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The vertical panels that separate cells in a canopy
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RISERS
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Suspension lines. The lines that attach a harness to the canopy and hold the canopy’s angle of attack
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ROLL
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Is the lifting and dropping of the wing tips
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ROTOR
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An organized swirl of air behind a cliff face, mountain, building or tree. Must be avoided at all cost.
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SAHPA
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South African Hangliding and Paragliding Association
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SAT
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An acrobatics manoeuvre done by pilots with experience.
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SCRATCHING
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Flying low, close to the ground in hope of hooking a thermal. Can be dangerous.
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SINK
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Falling air which makes the glider travel downwards faster than normal
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SIV
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Simulations of Incidents en Vol (in flight). A paragliding safety clinic where pilots intentionally deflate their wing and learn to re
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SOARING
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Flight extended beyond the normal glide path of the glider.
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SPAN
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The total width of a glider from tip to tip.
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STABILITY
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Tendency for a glider to return to level flight from any altitude or bank.
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STABILIZER
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A flap or series of cells at the ends of a canopy to help hold its
spread.
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STALL
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A sudden loss of lift and increase in drag due to an excessive angle of attack.
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STALLING TURN
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A turn with too much inside brake applied, resulting in a dropping back of the inside wing followed by a dive.
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STEERING LINES
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The control or brake lines used to steer a glider or change its speed
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TAILWIND
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A wind from the rear or in the direction of heading
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TANDEM
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Flying with two persons on a glider
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TELL-TALE
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A piece of yarn or cloth on the glider top tell wind direction at
take-off
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TFI
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Training Flight Instructor
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THERMAL
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A mass of warm rising air providing lift. The best place is to be right in the centre. Pilots obey rules of the road when flying in a thermal together.
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THUNDERSTORM
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A large convective cell that features violent weather in the form of high winds, turbulence, lightning and hail.
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TOGGLES
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The hand receptacles or loops at the end of a steering (brake) line
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TOW LINES
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The line used to tow gliders with a vehicle
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TRAILING EDGE
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The rearward part of the wing
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TURBULENCE
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Gusts or swirls of air encountered in flight.
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UPWIND
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A flight direction heading into the wind.
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VARIOMETER
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An electronic device that indicates when the glider is rising and sinking as well as altitude.
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VORTEX (TIP VORTICLES)
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The swirling of air at the tips of a glider
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WALL
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A preliminary step before every inflation where the pilot inflate the wing's leading edge and builds tension on the lines. A wall allows the pilot to determine that none of the lines are tangled and that the wing tips are not tucked in (cravatted).
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WIND GRADIENT
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Slowing of the wind as the ground is approached
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SIND SOCK
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A cloth tube mounted on a pole to indicate wind direction
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WING LOADING
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The weight-to-area ratio on an aircraft found by dividing the flying weight of the pilot plus the glider by the total sail area
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XC
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Acronym for Cross Country flying
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YAW
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The motion of a wing whereby one side moves forward and the other moves back.
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