Contrails and Climate Change

Dean Sigler Diesel Powerplants, Sustainable Aviation Leave a Comment

Contrails are the trails of condensed water vapor that follow an airplane at a high enough and cold enough altitude.  They became a visible presence in World War II and were part of newsreels of allied bombers hitting Germany and dog fights over the English countryside.  There was more than just an aesthetic side to the new, high clouds in the sky, though. Post-9/11 During the attacks on September 11, 2001, FAA controllers, “Did the only thing they could think of to try to control the situation: ordering every aircraft in U.S. airspace, about 4,000 of them, to land somewhere, anywhere, immediately.” “Canadian officials followed. Airports in Atlantic Canada quickly filled with thousands of bewildered people who had been flying west across the Atlantic from Europe, but found themselves stranded in Goose Bay, Labrador or Stephenville, [Newfoundland].” Following this mass grounding, an observable cooling took place.  Andrew Carleton, a geographer at Pennsylvania State University recalled his observations at the time.   “I remember walking …

Electric, Small, and Challenging

Dean Sigler Electric Powerplants, Sustainable Aviation 4 Comments

Dr. Ilan Kroo, a professor of aeronautics and astronautics at Stanford and designer of the Swift ultralight hang glider, among others, has a different kind of mission – that of reshaping small aircraft for the greatest efficiency. Lessons learned from light aircraft can be applied on a larger scale – but keeping it simple and light to begin with allows less expensive learning, according to Kroo. The outline for his presentation at the fifth annual Electric Aircraft Symposium in Santa Rosa, California on April 29, 2011 is instructive. He had three major topics, all repeating the title for his talk; “Design Concepts for Small Electric Aircraft.” The first topic emphasized the word, “Electric,” the second, “Small,” and the third, “Design Concepts.” First he discussed why electric aircraft are of interest, including their environmental impact, efficiency, reliability, energy source independence, and that fact that they are scalable – the latter being important to anyone also designing lifting body airliners. Modern airliners …