EDWARDS AIR FORCE BASE – With the graceful flight of hawks and eagles in mind, NASA aerospace engineer Michael Allen hand-launched a lightweight motorized model sailplane over Rogers Dry Lake, hoping it would catch plumes of rising air called thermals. It did just that numerous times, validating his premise that using thermal lift could significantly extend the range and endurance of small unmanned aerial vehicles without carrying more fuel. “The flights demonstrated that a small UAV can mimic birds and exploit the free energy that exists in the atmosphere,” Allen said. Allen noted that a small, portable UAV with long-endurance capabilities could fulfill a number of surveillance roles including forest fire monitoring, traffic control and search and rescue. He said this technology might also have an application to flight on Mars where dust devils have been observed. Nicknamed Cloud Swift after a bird known for feeding on insects found in rising air masses, the 14-foot-wingspan remote-controlled RnR Products sailplane flew 17 times over an eight-week period from July through mid-September. The model sailplane was modified to incorporate a small electric motor and an autopilot, the latter reprogrammed to detect thermals or updrafts. Dryden aerospace technician Tony Frackowiak guided the model to an altitude of about 1,000 feet and then handed off control to the sailplane’s autopilot. The software flew the aircraft on a predetermined course over the northern portion of Rogers Dry Lake until it detected an updraft. As the aircraft rose, the engine automatically shut off and the aircraft circled to stay within the convective lift resulting from the updraft. “I have some experience flying radio-controlled sailplanes and working the lift manually as an RC pilot. The autopilot looked like it was doing a good job of detecting and using the lift in certain conditions,” said Frackowiak. Allen said the small UAV added 60 minutes to its endurance by soaring autonomously, using thermals that formed over the dry lake bed. The model gained an average altitude in 23 updrafts of 565 feet, and in one strong thermal ascended 2,770 feet. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!