NASA is testing a 10-engined prototype battery-powered VTOL (Vertical Take Off and Landing) aeroplane. The 10-foot wingspan GL-10 plane, codenamed Greased Lightning, is currently being put through a rigorous design and testing phase at NASA’s Langley Research Center in Virginia, and is meant as the precursor to an even larger, 20-foot wingspan model, which may be an unmanned aerial vehicle (UAV).
“We have a couple of options that this concept could be good for,” said aerospace engineer Bill Fredericks. “It could be used for small package delivery or vertical take off and landing, long endurance surveillance for agriculture, mapping and other applications. A scaled up version—much larger than what we are testing now—would make also a great one to four person size personal air vehicle.”
David North, a member of the GL-10’s engineering team, added, “We built 12 prototypes, starting with simple five-pound (2.3 kilograms) foam models and then 25-pound (11.3 kilograms), highly modified fiberglass hobby airplane kits all leading up to the 55-pound (24.9 kilograms), high quality, carbon fiber GL-10 built in our model shop by expert technicians.”
“Each prototype helped us answer technical questions while keeping costs down. We did lose some of the early prototypes to ‘hard landings’ as we learned how to configure the flight control system. But we discovered something from each loss and were able to keep moving forward.”
With initial tests promising – the GL-10 has passed its hover test, taking off vertically and hanging in the air like a helicopter – the biggest hurdle was to transition the craft from hovering to flying.
“During the flight tests we successfully transitioned from hover to wing-borne flight like a conventional airplane then back to hover again. So far we have done this on five flights,” Fredericks said. “We were ecstatic. Now we’re working on our second goal—to demonstrate that this concept is four times more aerodynamically efficient in cruise than a helicopter.”
The next test will assess the GL-10’s aerodynamic efficiency, and NASA engineers are optimistic that Greased Lightning will prove a success.
Thank you phys.org for providing us with this information.