glidin

Glidin, or gliding, is a form of flight in which an aircraft moves through the air without propulsion. In aviation, gliding relies on lift generated by wings and on the pilot exploiting naturally occurring updrafts, such as thermals, ridge lift, or waves, to stay aloft and gain altitude.

Most gliders, or sailplanes, have long, slender wings and lightweight construction to achieve a high lift-to-drag ratio. They are typically launched by aerotow behind a powered aircraft or by a ground-based winch, and then flown by manual control and instrumentation. Flight involves circling in rising air to climb, followed by long glides between lift sources. A key performance metric is the glide ratio, the distance traveled forward for each unit of altitude lost.

History of gliding began in the late 19th century with pioneers who demonstrated controlled flight without engines. In the 20th century, sailplanes evolved with better airfoils, lighter materials, and optimized aerodynamics. After World War II, advances in composites and instrumentation produced modern sailplanes used for sport, training, and cross-country flights.

Training and competition are central to glidin. Pilots typically undergo formal instruction to learn aerodynamics, meteorology, and cross-country planning, and to earn appropriate certifications. Major events include world championships organized under the Fédération Aéronautique Internationale (FAI). Gliding encompasses a range of aircraft, from two-seat training gliders to high-performance single-seat competition sailplanes, as well as self-launching motor gliders.

In modern use, glidin also includes variants such as motor gliders that carry propulsion for self-launch and extended range, while the core idea remains the sustained, unpowered flight driven by natural lift and skillful piloting.