Image: NASA Langley/David C. Bowman
A NASA research team at NASA's Langley Research Center in Hampton, Virginia, has successfully tested their unmanned VTOL prototype aircraft, questionably named Greased Lightning, or more formally GL-10. All John Travolta jokes aside, “We have a couple options that this concept could be good for,” said Bill Fredericks, aerospace engineer. “It could be used for small package delivery or vertical take off and landing, long endurance surveillance for agriculture, mapping and other applications.”
The initial plan was to develop a 20-foot wingspan (6.1 meters) aircraft powered by hybrid diesel/electric engines, but the team started with smaller versions and progressed with different prototypes. “We built 12 prototypes, starting with a simple five-pound (2.3 kilograms) foam models,” said aerospace engineer David North. “Each prototype helped answer technical questions while keeping cost down.”
Image: NASA/Gary Banziger
The beginning of the video is not exactly super exciting stuff, but if you can get through the amazing screwdriver action you will be rewarded with some actual flight footage. After take off the GL-10 doesnt appear extremely stable in a hover but it does make the difficult aerodynamic transition from hover to “wing-borne” flight like a champ. "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," said Fredericks. The next goal is "to demonstrate that this concept is four times more aerodynamically efficient in cruise than a helicopter.” Zack Johns, the GL-10’s primary pilot says "flying the ten-engine aircraft has its ups and downs" - I assume no pun was intended. Johns says from a control perspective it flies like any other three-engine aircraft. “All four engines on the left wing are given the same command,” says Johns. “The four engines on the right wing also work in concert. Then the two on the tail receive the same command.” Johns didn’t explain his unique way of flying the aircraft with the radio transmitter pointed down but knowing NASA, he may be onto something so next time I fly I’m pointing my transmitter down! But wait then I wont be able to see the monitor… scratch that.