On a Smaller Scale: NASA’s Flight Research UAVs

NASA Langley Research Center’s GL-10 Greased Lightning is a subscale model of a hybrid-electric distributed-propulsion unmanned aircraft with tilting wing and tail that would be able to take off and land vertically and fly for up to 24 hr. Seen here being tether-tested before free-flight tests, the 10-ft.-span GL-10 weighs 55 lb. and is battery powered. Credit: NASA

NASA Armstrong Flight Research Center’s Droid unmanned research aircraft tows a third-scale model of the Towed Glider Airborne Launch System (Tgals) into the air over Edwards AFB, California. The 27-ft. span twin-fuselage glider (inset images) is a model of a remotely or optional piloted glider that would be towed aloft by a transport aircraft and release a booster rocket at 40,000 ft. to place a payload into orbit. Credit: NASA

Delivered to NASA Armstrong in October, the Ptera was developed by Area-I as a low-cost, low-risk testbed for advanced controls and configurations. Modeled on the Boeing 737, the 11.3-ft.-span UAV has two model jet engines. A second Ptera, modeled on the Bombardier CRJ700 with 12-ft. span and rear-mounted engines, will be used by NASA Langley for T-tail loss-of-control research. Credit: NASA

Transferred from the Air Force Research Laboratory to NASA Armstrong, the Lockheed Martin Skunk Works X-56A will be used to develop active flight controls and advanced shape sensors enabling slender, flexible wings that will reduce the weight and drag of future airliners. The 480-lb., 28-ft.-span flying wing is powered by two small turbojets and has interchangeable wing sets. Credit: NASA

This APV-3 unmanned aircraft was modified by NASA Aeronautics Academy summer interns at Armstrong to flight-test technology to sense and redistribute airloads on a wing in real time. A fiber-optic strain- and shape-sensing network was connected to an autopilot that sent individual commands to 44 trailing-edge flap segments (top image) to reduce loads on the long-span wing. Credit: NASA

Prandtl-D was a 12.3-ft.-span scale model of a flying wing with a non-elliptical lift distribution, built and flown by NASA Aeronautics Academy interns. Resembling the Horten flying wings of the 1940s, the radio-controlled glider confirmed German aerodynamicist Ludwig Prandtl’s theory that changing the lift distribution at the wing tips could turn adverse yaw due to induced drag into beneficial proverse yaw. Credit: NASA