81.5-Hour Solar Flight – Best in Class

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Following Andre’ Borschberg’s record-breaking endurance and distance flight in Solar Impulse last month, the accomplishment of a group of Swiss students and their planned trans-Atlantic, solar-powered autonomous flight are equally worthy of consideration. With a much smaller budget than Solar Impulse, the students are planning a 5,000 kilometer (3,100 mile) flight from Bell Island, Canada to Lisbon, Portugal, a seven-day test of self-guided navigation and autonomous airmanship.  Recent achievements by the team suggest that success will come from good design and careful planning. Last month, their AtlantikSolar 2 Unmanned Aerial Vehicle made its first 24-hour flight.  (The team generously acknowledges American Alan Cocconi’s 48-hour, solar-powered flight with his 13-kilogram (28.6 pound) So Long in 2005.) Only two weeks later, the …

Ion Tiger Exceeds 48 Hours in Flight

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Researchers at the U.S. Naval Research Laboratory flew their fuel cell powered Ion Tiger UAV for 48 hours and 1 minute on April 16-18 by using liquid hydrogen fuel in a new, NRL-developed, cryogenic fuel storage tank and delivery system. This flight shatters their previous record of 26 hours and 2 minutes set in 2012 using the same vehicle, but with gaseous hydrogen stored at 5000 psi.  The airplane had flown 23 hours, 17 minutes in 2009. The 550 Watt (0.75 horsepower) fuel cell onboard the Ion Tiger has about four times the efficiency of a comparable internal combustion engine and the system provides seven times the energy in the equivalent weight of batteries.  The Ion Tiger weighs approximately 37 …

Dr. Jack Langelaan and Heuristic Navigation Techniques

Dean Sigler GFC, Sustainable Aviation 1 Comment

“Heuristic: involving or serving as an aid to learning, discovery, or problem-solving by experimental and especially trial-and-error methods ; also: of or relating to exploratory problem-solving techniques that utilize self-educating techniques (as the evaluation of feedback) to improve performance ”  m-w.com (Merriam-Webster online)  Dr. Jack Langelaan’s talk at the fifth annual Electric Aircraft Symposium was one of at least two to use the term, “heuristic,” and sent this writer scrambling for the dictionary. His presence in Santa Rosa, four months ahead of his return with the Green Flight Challenge winning Pipistrel G4, showed at least one of the facets to the planning that would make the G4 victorious. Careful flight planning, as any flying instructor will gladly inform you, is …

163 Horsepower from 25 Pounds

Dean Sigler Electric Powerplants, Sustainable Aviation 4 Comments

ThinGap, LLC is well known for small motors with excellent performance characteristics, eliminating the use of iron and its resultant “lossiness” and depending instead on copper foil, rather than wire windings for its internally clean structure. The design leads to a lack of “cogging,” that notched feeling found when turning over some motors by hand.  Each individual magnet causes the rotor to stop, or “cog,” sometimes making low-speed operation a bit hesitant and smooth transitions difficult.  That, the unique ring design and an aluminum housing help carry heat away and allow for an internal controller. ThinGap have focused on smaller unmanned aerial vehicle applications for many years, but have moved into larger automotive and aircraft products, with one model in …