Gliders

Gliders, or sailplanes, are aircraft designed to fly without an on-board engine. They rely on atmospheric lift and skilled piloting to stay aloft. Wings are long and slender to maximize lift-to-drag ratio, giving them high gliding efficiency. Launch is usually by aerotow or ground-based winches; some models use small auxiliary engines for self-launch or extended flight (motorgliders). In flight, pilots seek rising air—thermals, ridge lift, or mountain waves—to gain altitude and extend distance.

Gliding has its roots in the late 19th century with aviation pioneers such as Otto Lilienthal. Through the early to mid-20th century, gliding clubs, standardized training gliders, and international competitions helped establish it as a sport. After World War II, advances in aerodynamics and materials led to modern sailplanes with excellent performance, and today composite construction enables very high performance.

Most gliders have an enclosed cockpit and a high aspect ratio wing; earlier types used wood and fabric, while modern aircraft use fiberglass, carbon fiber, and other composites. They commonly incorporate airbrakes or spoilers for descent control, and may have retractable landing gear. Motorgliders mount a small engine for self-launch or extended flights.

Typical glide ratios range from about 40:1 to over 60:1; sink rates allow sustained flight in rising air, with speeds varying across models. Gliding is practiced worldwide as a sport, for pilot training, and in cross-country competitions. It requires favorable weather and careful planning to exploit atmospheric lift while observing airspace and safety regulations.