Havilland invented a simple and practical linkage and their de Havilland Tiger Moth classic British biplane became one of the best-known aircraft, and one of the earliest, to use differential ailerons. Roll control without ailerons Wing warping On the earliest Pioneer Era aircraft, such as the Wright Flyer and the later, 1909-origin Blériot XI and Etrich Taube, lateral control was effected by twisting the outboard portion of the wing so as to increase or decrease lift by changing the angle of attack. This had the disadvantages of stressing the structure, being heavy on the controls, and of risking stalling the side with the increased angle of attack during a maneuver. By 1916, most designers had abandoned wing warping in favor of ailerons. Researchers at NASA and elsewhere have been taking a second look at wing warping again, although under new names. The NASA version is the X-53 Active Aeroelastic Wing while the United States Air Force tested the Adaptive Compliant Wing. Differential spoilers Spoilers are devices that when extended into the airflow over a wing, disrupt the airflow and reduce the amount of lift generated. Many modern aircraft designs, especially jet aircraft, use spoilers in lieu of, or to supplement ailerons, such as the F4 Phantom II and Northrop P-61 Black Widow, which had almost full width flaps (there were very small conventional ailerons at the wingtips as well). Roll induced by rudder All aircraft with dihedral have some form of yaw-roll coupling to promote stability. Common trainers like the Cessna 152/172 series can be roll controlled with rudder alone. The rudder of the Boeing 737 has more roll authority over the aircraft than the ailerons at high angles of attack. This led to two notable accidents when the rudder jammed in the fully deflected position causing rollovers (see Boeing 737 rudder issues). Some aircraft such as the Fokker Spin and model gliders lack any type of lateral control. Those aircraft use a higher amount of dihedral than conventional aircraft. Deflecting the rudder gives yaw and a lot of differential wing lift, giving a yaw induced roll moment. This type of control system is most commonly seen in the Flying Flea family of small aircraft and on simpler 2-function (pitch and yaw control) glider models or 3-function (pitch, yaw and throttle control) model powered aircraft, such as radio-controlled versions of "Old Timer" free-flight engine-powered model aircraft. Other methods Weight-shift control