Birds fly without flaps. The wings that propel birds and winged mammals through the sky are flexible, organic forms that smooth-shift feathered limbs or a canvas of skin to adjust for pitch and yaw, angling the creature through the sky. Human-created fixed-wing aircraft have, for over a century, relied on rigid control surfaces and distinct flaps to steer in flight. A new wing, tested on a drone by the Air Force Research Laboratory, wants to change that, offering flapless flight to future fliers.
Called the Variable Camber Compliant Wing, the new form features a “continuous skin” membrane, which can bend and warp to alter wing shape to the same effect as flaps in conventional aircraft. What is different is that the smooth, consistent plastic surface allows for quieter, more aerodynamic flight. It also, by reducing the need for distinct parts and harsh edges, is a lighter mechanism than a traditional flapped wing.
“Early estimates show [Variable Camber Compliant Wing] technology saving aircraft fuel consumption by 10 percent,” said Dr. James Joo, AFRL Advanced Structural Concepts team lead and VCCW program manager. “This was one of our main goals, and it fits the Air Force’s efforts to reduce overall energy costs.”
In 2018, Joo was awarded a patent for an early version of the wing, which allows “continuous wing reconfiguration that optimizes wing geometry for current altitude, airspeed, and lift-to-drag ratio requirements.”
The flight demonstrations took place in fall 2019, with an 8 ft. wing mounted on a commercial off-the-shelf drone. The promise is that such flapless wings could increase both fuel efficiency and control for long-range flights. If the wing continues to perform in tests, it could lead to a change in aircraft design, ushering in a whole unflappable era of flight.
Watch it in action below: