nasa to test in flight folding wing page: 1 link nasa is set to begin testing a new wing design that would change shape in flight, bending up or down, to increase yaw stability, reduce required rudder size, and decrease drag. the boeing 777x is set to introduce wingtips that fold on the ground, to allow the aircraft to fit in existing gates with a longer wingspan. nasa is set to begin testing the spanwise adaptive wing, which would add shape-memory alloy actuators to the wingtip area that would bend the tips up or down. the sma actuators would activate when heated electrically, so there is no need for complex hydraulic lines or actuators. beginning in spring of 2017, nasa will start flying the area-i ptera uav. it has a 176 inch wingspan, with the outer 15 inches moving as far as 75 degrees up or down. ptera is not set up for saw, but it appears that it could see a 40% rudder authority. the idea behind saw is similar to what was done with the xb-70, with the wingtips angled down. boeing will introduce folding wings to commercial aviation when the 777x airliner enters service at the end of 2019. but the devices could become commonplace on future aircraft as wingspans increase in an effort to reduce drag and fuel burn. the 777x has almost 24 ft. more wingspan than today<u+2019>s 777 to optimize lift distribution and maximize cruise efficiency. folding the tips on the ground keeps the larger aircraft compatible with existing taxiway and gate size restrictions. but nasa is investigating whether also folding the wing in flight could save still more fuel. the spanwise adaptive wing (saw) concept will be tested on the ground and in flight in a rapid feasibility assessment under nasa<u+2019>s new convergent aeronautics solutions project. the goal is to show that angling the outboard wing sections up or down can increase yaw stability and control, and reduce rudder size and tail drag.
nasa to test in flight folding wing
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