Taja Boscarol, Public Relations Manager for Pipistrel, sends this news today: “The Pipistrel Taurus G4, world’s first 4-seat electric aircraft, was nominated for the prestigious Collier Trophy. “The Collier Trophy, the ‘Greatest Award in Aviation,’ has been the benchmark of aviation and aerospace achievement for over 100 years. Awarded annually, ‘…for the greatest achievement in aeronautics or astronautics in America,’ it has been bestowed upon some of the most important projects, programs, individuals, and accomplishments in our nation’s history.” Collier-winning individuals have included the crews of Apollo 11 and 8, Mercury 7, Scott Crossfield, Elmer Sperry and Howard Hughes. Projects and Programs have included the B-52, Polaris Missile, Surveyor Moon Landing Program, Boeing 747, Cessna Citation, Gulfstream V, the F-22 and the International Space Station. This year’s nominees for the 2011 Robert J. Collier Trophy are Boeing’s 787 Dreamliner, the Lockheed C-5M Super Galaxy, the Gamera human-powered helicopter, and the G4. National Aeronautics Association Chairman Walter J. Boyne explains the …
Better Batteries: Powers of Ten
The CAFE Foundation in its Electric Aircraft Symposia has put forth the idea of the 10X battery for many years. Dr. Seeley therefore found a great deal of excitement in the following news. Researchers at Northwestern University in Evanston, Illinois have perhaps achieved part of that dream, with a graphene and silicon anode that yields a 10-times-faster charge and can hold a charge 10 times greater than that of a typical lithium-ion battery. Claiming their technology will be on the market in three to five years, the researchers have published a paper describing the research in the journal Advanced Energy Materials. A University press release explains. “’We have found a way to extend a new lithium-ion battery’s charge life by 10 times,’ said Harold H. Kung, lead author of the paper. ‘Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today.’ (Meaning …
How Green was GFC Electricity?
The blog received several comments about the relative energy use of electric aircraft, and how NASA and the CAFE Foundation might have overstated the efficiency and low emissions for the electric aircraft in the competition. Reader Robert Swanson thought the conversion between kilowatt hours and gasoline created a discrepancy. “The discrepancy in performance of gasoline and electric powered aircraft is due to an absurd conversion factor between kWh and gallons of gasoline. The conversion should be calculated from the number of gallons of gasoline consumed by the engine driving the generator used to charge the batteries.” Steven Crow added this objection. “Even after reading the relevant pdf’s, it is far from clear to me how CAFE computed ‘mileage’ for the electric aircraft. The right way of doing it is clear enough: base the mileage on the fossil fuel used to charge the batteries. Electric motors and batteries are not subject to Carnot efficiency limitations. They can seem to be nearly …
Green Flight Challenge Final Results
Steve Williams, CAFE Foundation board member and e-totalizer guru, released the final results for the NASA Green Flight Challenge sponsored by Google, held at the Charles M. Schulz Sonoma County Airport from September 25 through October 1, 2011. Figures show a profound difference between the two electric winners and the two gas-powered and hybrid runners-up. All competitors flew extremely clean motorgliders with demonstrated lift-to-drag ratios between 25:1 and 35:1. Possible explanations for the large differences in energy use include low cooling drag for electric aircraft and the efficiency of electric motors – but the differences are still surprising. Note that a little over 11 US gallons of gasoline (energy equivalent) were used to fly seven people (Embry Riddle’s Eco-Eagle flew with only one pilot) over a total of 725.5 miles (Embry Riddle flew a shorter total distance on both “runs”). This is an enormous achievement for all concerned and a significant increase in efficiency over even the best general aviation craft available today. Congratulations are …
NASA Adds Some Numbers to Green Flight Challenge
NASA’s Mark Moore sends this link to NASA’s press release on the recent NASA Centennial Challenge Green Flight Challenge sponsored by Google. The CAFE Foundation organized and managed the event. “Today we’ve shown that electric aircraft have moved beyond science fiction and are now in the realm of practice.” – Chief technologist at NASA Joe Parrish. The lead quote is informative, as are some figures from the release. “The competition resulted in the world’s most efficient aircraft, beating the state of the art of approximately 100 pmpg (passenger miles per gallon) which is achieved by the newly released Boeing 787 airliner. Essentially this contest showed the ability of small aircraft to achieve twice the efficiency of the most efficient production automobiles today, while traveling at over twice the speed.” Part of this efficiency came about because of inspired design. NASA explains, “The Taurus G4 used a multi-body concept (reminiscent of the twin Mustang, or an inverse P-38); this accomplished a 61% useful …
AVweb Readers Weigh In on Electric Aircraft, Green Flight Challenge
Mary Grady of AVweb started an expanding dialogue with her recent opinion piece on NASA and the CAFE Foundation’s Green Flight Challenge sponsored by Google. The stimulating and varied points of view reflect what is probably floating around in the general public’s perception of “green aviation,” ranging from total ignorance of what has been done already, to confusion about what it all means, to well-honed, technically aware arguments on both sides of the issue. Her thought that electrification is, “the first step down a long and bumpy road that could take general aviation in new directions,” was reinforced with the following reflections that might be similar to those that readers of this blog often experience. “For people who fly for fun — presuming there are many of those left, it seems to be one of the fastest-shrinking segments of GA — electric airplanes are sure to appeal. They are easier to deal with, and quieter, with less vibration. A few …
The G4 Gets Off the Grass
Pipistrel had a good week at Oshkosh. Shortly after its G4 placed ninth in the Dead Grass Awards, an indication of the number of spectators who tramped around the perimeter of the displayed aircraft, the company could announce the first test flight of the four-seat electric motorglider. “We are pleased to announce that after long and demanding work nearly of a nearly 30-member team of developers and constructors from Pipistrel’s R & D Institute the first 4-seat electric aircraft in the world took off this morning [August 12, 2011] at 7 AM local time.” Pipistrel overcame several difficulties in achieving this milestone. Developing the electric power system, the most powerful currently in an aircraft, and importing the 450 pounds of lithium-polymer batteries needed to energize it presented many issues. Perhaps the utterly new and unique design and the possibility of that many batteries self-igniting caused insurance companies to be more than normally cautious, although one did finally step forward. Because …
David Birkenstock and Ultimate Efficiency
According to his biography on Airliners.net, “David Birkenstock is a pilot for an east-coast charter and management firm, flying the Turbo Commander 690B and the BeechJet 400A. When he’s not flying, he’s working on modifying a light sport airplane for pressure thrust, hoping to enter it into the NASA Personal Air Vehicle Challenge. He has posted more information about pressure thrust at PressureThrust.com.” Birkenstock’s presentation at the fifth annual Electric Aircraft Symposium in Santa Rosa, California on April 29, 2011 extended his thoughts on pressure thrust, an outgrowth of Fabio Goldschmied’s theories that are well represented in the CAFE Foundation’s library. Most surprising (or maybe not surprising at all) in his talk were comments by major players in the aerospace industry. Around 2000, a senior airflow fellow for a “major airframe manufacturer was quoted as saying, “Our position is that aviation is a mature business and that the discoveries waiting to be identified are probably not worth looking for, much …
Google to Sponsor Green Flight Challenge
Green Flight Challenge sponsored by Google to bring historic firsts to aviation Aviation’s largest ever prize to be awarded at Moffett Field October 3 during exposition hosted by NASA SANTA ROSA, CA (July 29, 2011) – The CAFE Foundation announced today that Google will sponsor the NASA Centennial Challenge flight competition known as the Green Flight Challenge (GFC). CAFE (Comparative Aircraft Flight Efficiency) will conduct the event from September 25 through October 2, 2011 at Charles M. Schulz Sonoma County Airport. The NASA-funded prize purse of $1.65M makes this the largest ever prize for aviation. Competing aircraft must demonstrate at least 100 mph and 200 passenger MPG on a 200 mile flight. The aircraft in the Green Flight Challenge sponsored by Google represent a diverse mix of singular prototypes created expressly for the competition by some of the world’s top designers. Most will be propelled by batteries and electric motors, some by bio-fuel or hybrid. All competing aircraft will be …
A Useful Spreadsheet and GFC Handicapping Tool
For analyzing the greatest economy from an aircraft’s design, Howard Handelman, a highly-engaged reader of this blog, provides a link to his web site, which includes a downloadable spreadsheet he has devised that will give the inquiring reader hours of enjoyment. Handelman, self-described as, “just a retired IT guy,” with “weak math skills,” but a “compulsively curious” nature, has devised a tool for analyzing any airplane’s performance based on a few known variables, and which he has applied to many of the Green Flight Challenge’s aircraft. The basis for his analyses is his “triangle tool,” a wedge that can be used to help design propellers, “test [the] truth” of claimed aircraft performance, and estimate brake horsepower in real life circumstances (at least within the parameters of the triangle tool). Handelman notes that some aircraft, including those with laminar flow, will “not fit the model very well because they don’t fit the V-squared curve. Synergy won’t look anything like the model.” His findings …