NASA’s new battery-powered, 10-engine aircraft takes off, hovers, and lands like a helicopter -- yet flies efficiently like a plane. It shifts between vertical and forward flight while up in the air. Called Greased Lightning or GL-10, a prototype with a 3-meter (10-foot) wingspan just completed its first few successful flights with midair conversions this spring at Fort A.P. Hill, a military base in Virginia.
"During the flight tests we successfully transitioned from hover to wing-borne flight like a conventional airplane then back to hover again," Bill Fredericks of NASA’s Langley Research Center says in a news release. So far, they’ve done this on five flights.
In its latest version, the remotely piloted plane has eight electric motors on its wings and two electric motors on the tail. The four on each of the wings are given the same command, as are the two on the tail. So, according to Greased Lightning’s primary pilot, Zack Johns, it flies like a three-engine plane from a control perspective. It weighs up to 28 kilograms (62 pounds) and is much quieter than mowing the lawn with a powered motor.
The team has built 12 prototypes using materials ranging from foam to fiberglass to carbon fiber. “Each prototype helped us answer technical questions while keeping costs down,” David North of NASA's Langley says. “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."
There are a wide range of things Greased Lightning could be really good for, especially if it can be made into an unmanned aerial vehicle (UAV). "It could be used for small package delivery or vertical take-off and landing, long endurance surveillance for agriculture, mapping and other applications,” Fredericks adds. “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."
Now that they’ve shown how Greased Lightning can basically launch anywhere a 'copter can, the team’s next goal is to demonstrate that their concept is four times more aerodynamically efficient in cruise than a helicopter.
It’s being showcased at the Association for Unmanned Vehicles Systems International 2015 conference in Atlanta this week. Watch a cool video of the transition test here:
Update: The previous video has been replaced with the correct one.