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How To Talk Sailplane

Aileron: Ailerons are hinged control surfaces attached to the trailing edge of the wing of a fixed-wing aircraft. The ailerons are used to control the aircraft in roll.


Aspect Ratio: Also known as AR, the aspect ratio of a wing is the length of the wing compared with the breadth (chord) of the wing. A high aspect ratio indicates long, narrow wings, whereas a low aspect ratio indicates short, stubby wings.


Binnacle: The “dashboard” that hold the instruments in the cockpit of a glider.


Canopy: The plastic bubble over the pilot’s head.


Canopy Latch: A small lever or sliding pin used to hold the canopy in place when closed.


Center of Gravity or CG:  The point at which an aircraft would balance if it were possible to suspend it at that point. It is the mass center of the aircraft, or the theoretical point at which the entire weight of the aircraft is assumed to be concentrated. The center-of-gravity point affects the stability of the aircraft. To ensure the aircraft is safe to fly, the center-of-gravity must fall within specified limits established by the manufacturer.


Elevator: Horizontal control surfaces at the back of the tail used to control pitch.


Fin: Commonly referred to as the Rudder, is the vertical tailpiece connected to the boom of the sailplane. The rudder is the movable part connected to the Fin.


Flaps:  Trailing edge surfaces beginning at or near the fuselage and extend out to the aileron. These surfaces can be drooped slightly to increase lift, raised or reflexed to decrease lift and increase speed, or extended downward significantly increasing lift at slowing the plane for landing.


Flaperons:  Usually a control surface along the entire trailing edge of the wing which functions as both flaps and ailerons. The mixing of the flap to aileron is normally done with a computer radio system.


Fuselage or “Fuse”: The central body of the sailplane or tug.


Horizontal Stab: The entire horizontal tail part. Usually one part is stationary the trailing part is the elevator. Sometimes there is not elevator and the entire part pivots to control the pitch. This is called a “full flying stabilizer.”


Lift-To Drag or L/D: The lift-to-drag ratio, or L/D ratio (“ell-over-dee”), is the amount of lift generated by a wing, divided by the drag it creates by moving through the air.


Leading Edge: The front edge of the wing.


Lift: Rising air.  AKA “thermal.”


Match Box: This device, manufactured by JR, allows two servos to operate from one channel together and perfectly matched to work in unison, including reversing the travel direction of one servo.


Pitcheron: When both wings rotate in either opposite directions for roll control or in the same directions for pitch control.


Power Box: A central unit into which all the servos are plugged. The unit distributes power to the servos without running through the receiver.  A central distribution buss.


Pull-Pull: A cable most typically used on the rudder, this allows the rudder to have a cable attached to each side and then stretched to the control arm of the servo. When the rudder is deflected either way, it pulls the control surface.


Retract: The main wheel, which retracts into the belly of the sailplane. It’s commonly found on modern sailplanes.


Rudder: Vertical control surface at the back to the tail used to control yaw


Rudder Post: The internal post running up the back edge of the FIN, this post will have a cut out in it where the servo for the elevator is located.


Seat Pan:  Where the pilot will sit in the sailplane.


Servo Covers: Fiberglass or plastic covers that are installed over the servo after installation, typically in the wing and stabilizer.


Sink: Cool descending air, which as a sailplane pilot, you’ll want to avoid, typically found on the backside of a thermal.


Spoilers:  Any movable control surface that’s purpose is to reduce the lift provided by the wing. Not the same as airbrakes which are surfaces which are used to increase drag


Spoilerons:  Are a use of either Flaperon’s or Ailerons where they are deflected upwards to reduce lift and increase drag. Frequently used in landing planes that do not have flaps.


Stab or Stabilizer: The portion of the rear empennage inclusive of the elevator is known as the horizontal stabilizer, the rudder and fin as the vertical stabilizer.


Swivel or Snap Swivel: A strong snap swivel is used on the end of a towline which hooks into a loop inserted into the sailplane tow release.  Makes connection to the tow line quick and easy. Found at all fishing tackle shops.


Thermal: Warm rising air mass that sailplanes use to gain altitude.  AKA “lift.”


Tip: The end of the wing farthest away from the fuselage.


Towline: Line used to connect the Tug to the Sailplane.


Tow Release, Sailplane: A small device into which the tow loop in inserted.  The release is typically installed in the nose, however, there are a few occasions where it is installed on the bottom of the nose or even on the side of the fuselage.


Tow Release, Tug: This release is installed on the tow plane. It will be installed somewhere between the middle of the wing and the trailing edge area, on the top of the plane.  RC The towline will be connected to this release.


Tow Loop: A loop of line connected to the sailplanes nose release and connected to the towline, the tow loop will be a thinner and weaker line than the towline itself. The tow loop is the weak link; it should break if something goes wrong during the tow.


Trailing Edge: The rear edge of the wing.


Trilerons: A small triangular panel that is at the tip of the aileron and usually involves some twisting or bending of the hinge. The goal of trilerons is to seal the outer tip gap when the aileron deflects up or down. These do not have servos as they are attached to the aileron.


Tug: Tow plane used to pull up sailplanes.


Wing Root: The end of the wing at the fuselage.


Wingeron: This is when both wing are rotated in opposite directions to control roll of the airplane.


Select Soaring Phrases:


Dumb Thumbs: Pilot error resulting in a disruption of controlled flight or a crash.


Floater: Low wing loading and low sink rate glider


Full House: The glider will have Ailerons, Elevator, Rudder and Flaps.


Gasbag: Lightweight glider, typically a broad wing chord that does not want to come down


Great Legs: Often thought to only be referring to a woman’s get away sticks, but here in Glider world, “She’s got great legs” means that the glider has a great L/D and seems to cover a lot of ground easily and quickly.


Glass slipper: Fiberglass modern sailplane, low drag, very slippery


Hat Sucker: A very strong thermal


Porpoising: Pitch oscillations upward and down due to improper center of gravity or control surface trim.


Stick Thermal: Glider climbs momentarily because the pilot pulled back on the stick, not because he’s in a thermal.


Sucker Bump: That spot in the sky where you saw your glider climb very thermal like, only to find through multiple circles that you have begun a “slow death.”

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