Lift (soaring)

Although thermal lift was known to the Wright Brothers in 1901, it was not exploited by humans until 1921 by Wilhelm Leusch at the Wasserkuppe in Germany.

As it requires rising heated air, thermalling is only effective in mid-latitudes from spring into late summer.

During the off-season, when thermals are weaker, ridge and wave lift can still be used and some pilots travel to more mountainous areas to fly.

Provided that there is a steady increase in wind strength with altitude without a significant change in direction, standing waves may be created.

[6] These waves reach heights much greater than the original obstruction and so can permit gliders to climb to the stratosphere.

This lift is often marked by long, stationary lenticular (lens-shaped) clouds lying perpendicular to the wind.

[7] A mountain wave was used to set the record for highest altitude by a glider when Jim Payne and Tim Gardner soared to an altitude of 22,657 metres (74,334 ft) on September 2, 2018 over El Calafate, Argentina in the purpose-built Windward Performance Perlan II.

[8] The current world distance record of 3,008 km (1,869 statute miles) by Klaus Ohlmann (set on 21 January 2003)[9] was also flown using mountain waves in South America.

A rare wave phenomenon is known as Morning Glory, a roll cloud producing strong lift.

This is not true lift because the increase in potential energy of the aircraft is achieved from decreasing airspeed rather than the result of flying in rising air.