Free Flight (model Aircraft) - Gliders

Gliders

Gliders have no onboard motive power. The only energy inputs are the launch, and rising air encountered during the flight. During launch many gliders withstand 30G or more, far more than any manned aircraft is stressed to and launch speeds of sometimes over 140 km/h which energy is then converted in altitude ; this has only become possible since the advent of composite materials such as carbon (graphite), fiberglass, and Kevlar, which are used extensively in many of their structures.

The FAI glider class is F1A, also known as A/2 or Nordic glider. The model must have a projected area (wing and stabilizer) of between 32-34 dm2, and a minimum weight of 410 g. Launch is by hand tow, using a cable of 50 m length. The mini glider class is A/1 (F1H). A/1 gliders must have less than 18 dm2 total area, and weigh at least 220 g. Open glider contests are rarely flown, and most competitors in such contests use F1A gliders. Other glider classes include magnet-steered (F1E) gliders - essentially a free flight slope soaring class, and hand-launched glider (usually abbreviated HLG, and also widely known as simply chuck glider). HLGs are small models which are launched from level ground simply by being thrown hard. This is one of the more athletic of the free flight disciplines.