Sailplane Glider

Overview

The Sailplane Glider is a single-seat composite sailplane built for cross-country soaring. It has no engine. Once released from an aerotow or winch launch it stays aloft by working rising air, trading the height it loses through drag against the lift it finds in thermals, ridge wind and wave.

The airframe is glass- and carbon-fibre throughout. A slim pod-and-Fuselage carries the reclined Cockpit forward and tapers into a Tail Boom ending in a T-tail. The two long Wing panels give an 18 m span at an aspect ratio near 28, the geometry that lets the glider reach a 50:1 glide ratio: in still air it travels fifty metres forward for every metre of height lost. Every external surface is moulded to a laminar profile so the boundary layer stays attached and skin-friction drag stays low.

How it works

Lift comes from the wing; staying up is a contest between that lift and drag. A high aspect ratio narrows the wingtip vortices that cause induced drag, and the Winglet at each tip cuts them further. The reward is a low minimum sink rate, so the glider can circle tightly inside a thermal and climb with the air mass.

Between thermals the pilot flies faster, accepting a higher sink rate to cover ground quickly, a tradeoff the Glide / Flight Computer computes as speed-to-fly. On strong days the Water Ballast Tank in each wing carries water ballast: the extra weight raises the best-glide speed without hurting the glide ratio, then it is dumped before landing to lower the touchdown speed.

The pilot commands roll with the ailerons, pitch with the elevator and yaw with the rudder, all moved through the rigid pushrods and cables of the Flight Controls. To descend or steepen the approach, the top-surface Airbrake / Spoiler panels erect into the airflow and spoil lift on demand. A single retractable main wheel in the Landing Gear keeps drag low in flight and folds away once airborne.