Electricity in the sky: NASA’s Green Flight Challenge inspires new feats
Sometimes, goals and records aren’t just broken; they’re smashed.
Joe DiMaggio of the New York Yankees hit in 56 consecutive baseball games in 1941; the record before that was a mere 45 straight games.
Wayne Gretzky of the Edmonton Oilers hockey team scored 92 goals in a season once, in 1981-82; before the Great One’s remarkable feat the record for goals scored in an NHL season was only 76.
It’s not that the prior records weren’t good enough; it’s just that sometimes, accomplishments go way beyond what was thought possible.
Let’s take one more example: About two years ago the folks at NASA decided to come up with something called the Green Flight Challenge.
A part of NASA’s larger Centennial Challenges Program (prior competitions included the Personal Air Vehicle Challenge, and the Green Aviation Technology Challenge), the Green Flight Challenge set up some ambitious goals for aspiring aviators and engineers.
Trying to see exactly how far the idea of electric-powered airplanes could go, NASA asked competitors to build an airplane that was capable of going 200 passenger miles, in less than two hours, on the equivalent of less than one gallon of fuel per plane occupant, or the equivalent in electricity.
In addition, the planes in the challenge had to greatly reduce the ordinary noise level on a plane; NASA asked that the planes in the Challenge be 75 decibels or lower from 250 feet away.
“To make it easier to understand in car terms, let me put it like this,” said Sam Ortega, the program manager of the Centennial Challenges Program, clearly realizing that some people can’t quite yet get a handle on electric airplanes. “If one gallon of 87-octane gasoline equals 33.7 kilowatt hours of electricity, and you take a Toyota Prius that gets 40 miles per gallon, when you put five people into it, that’s 200 passenger miles, per mile per gas.
“So what we were trying to challenge people to do,” Ortega continued, “is build an airplane as efficient as a Prius, but go 100 miles per hour.”
It’ll sound naive in a few paragraphs here, but at the time Ortega said their 200-mile goal was thought by many to be impossible.
(photo of Pipistrel-USA Taurus G4, courtesy of NASA)
“We had a lot of pushback from people who thought we were crazy, that we were asking too much, and that the technology wasn’t really feasible yet, for this to happen,” Ortega said with a laugh. “As it turned out …”
As it turned out, the 200-mile barrier was way, way too conservative for two teams. A group led by Jack Langelaan of Penn State University in State College, Pa.,, teaming up with the technology and airplane experts at Pipistrel-USA, won first prize in the Challenge (awarded two weeks ago) by building a Taurus G4 that flew 403 passenger miles per gallon, more than double the original goal, during the competition’s final testing at Charles M. Schulz Sonoma County Airport in Santa Rosa, Calif. The winning plane flew 195 miles over a defined course, doing four (extremely quiet) laps over the California skies.
The Pipistrel-USA team won a first prize of $1.35 million.
Not to be outdone, a team from eGenius, of Ramona, Calif., also blew away the 200-mile barrier, building an aircraft that flew 378 passenger miles per gallon. (Fourteen entrants entered the competition originally, but when the final testing began last month, only four teams were able to make it to Schulz Airport for testing).
Clearly, with the 200-mile barrier, NASA set their sights too low, huh?
“I don’t know; two years ago when we started I didn’t really know if it was feasible,” admitted Langelaan from his office at Penn State, where he’s an assistant professor of Aerospace Engineering. “But once I started playing around with the numbers and seeing that it was possible, I got really excited and interested.”
After determining that the idea was feasible, Langelaan said he began researching possible aviation companies he could work with to achieve the goal.
He was intrigued by Pipistrel-USA ‘s Taurus.
“I saw it had a good combination of aerodynamic performance and that it was lightweight,” he said. “And they were selling it with an electric motor, and I knew it was efficient in converting electric energy from a battery.”
Langelaan’s journey toward the prize began in earnest during the summer of 2010, when he went to the EEA AirVenture Convention in Oshkosh, Wisc.
He met up with Pipistrel engineers and learned that the Slovenia-based company was already thinking about entering the Green Flight Challenge.
With Penn State’s aerospace engineering dept. firmly behind him, Langelaan and Pipistrel began to team up on what became a 10-month journey.
“We knew once we started to get into (entering the contest) that we’d be able to double the minimum that NASA was asking for, mileage-wise,” Langelaan said. “The Pipistrel people really did a great job with the propulsion system, and the power train. They did a super job to really make the airplane the best that it could be.”
Langelaan and NASA’s Ortega both agree that electric aircraft has a chance to greatly transform the industry. For one thing, electric planes are much, much quieter. This would have an enormous impact on regional airports around the U.S., who have to worry about neighborhood noise regulations.
“You have to realize that regional airports, some of them are being forced to close because of noise restrictions,” Ortega said. “If you could bring in small planes that make so much less noise, it would allow them to stay open for longer hours and do more business.”
Another appeal of electric planes is the cost of fuel: Lengelaan said that for $7 worth of electricity he can fly an airplane for three hours; it would cost him $70 in airplane fuel to do the same thing.
A third advantage to electric aircraft are the electric motors; Ortega said engineers and builders can install two electric motors into a plane, giving pilots a backup should one motor go bad.
Finally, electric motors have shown, so far, Ortega added, to be more efficient as compared to internal combustion motors. Ortega said electric motors are 60 percent more efficient.
Now, before you get too excited and call Delta and say you want to fly from New York to Denver on a new electric airplane, we are still a long way from commercial aircraft using electricity to fly the friendly skies. Right now only very small passenger planes, like the Pipistrel model above that won the Green Flight Challenge, are able to use electric power to fly.
“Right now Boeing and the other big companies have done some fuel cell-powered aircrafts, but nothing like the electric planes in the competition,” Ortega said. “I’d say right now electric airplanes are like where the Prius was about eight years ago; people look at it like it’s a novelty and aren’t really sure they want to buy them, or build them.”
Still, the accomplishments of the Pipistrel team, and the eGenius team, are certainly a step in the right direction.
Despite his newfound glory, Langelaan said that he won’t suddenly become a millionaire after leading the prize-winning team; he added that his share of the winnings will be placed in Penn State’s aerospace engineering research department.
For Langelaan, winning this competition is “the closest thing I’ll ever get to winning an Olympic gold medal. I’ll probably never win one of those, so this is the next best thing.”