Flexible wing

Early pioneer aeroplanes such as the Wright flyer used the flexible characteristics of lightweight construction to control flight through wing warping.

Predating successful controlled and powered flight, collapsible wings had been developed in an attempt to solve the problems of ground storage and transport.

A system of radial ribs like a giant folding fan, sometimes described as bat-like, was used by some pioneers, notably Gustave Whitehead in his attempts to build a flying car.

A relatively early example is provided by the flying-wing gliders of the Horten brothers during the 1930s, whose wing tips flexed upwards in flight to act as stabilising surfaces.

The aeroisoclinic wing, developed by Geoffrey T. R. Hill in the 1950s and flown on the Short SB.4 Sherpa, was an attempt control the flexing in such a way as to maintain handling characteristics in all flight regimes.

Following a series of talks in 1959 and 1960 his ideas spread rapidly and two designs in particular, the Rogallo delta and the paraglider, were soon being used for kites, hang gliders and ultralight aircraft.

Unlike the earlier kites it uses several struts to maintain its planform, while still relying on air pressure from beneath to develop its conical upper profile.

A flexible aerofoil can smoothly alter its shape to deflect the airflow, allowing the aerodynamic forces to be controlled without creating 'gaps' between hinges.