NEWS
On July 30, in a seminar during the AirVenture 2010 air show at Oshkosh, the future of air travel was also brought to the fore. The focus on e-aviation culminated in the World Symposium of Electric Aircraft and among the many interesting designs discussed was Boeing’s subsonic ultra green aircraft research (SUGAR) Volt concept—a hybrid engine design to run on jet fuel as well as electricity, which it is claimed, could reduce the fuel burn by more than 70 per cent. The concept could include hinges in the wing design so that they could be folded when on the ground. The airplane is designed to fly at Mach 0.79, carrying up to 154 passengers over 3,500 nautical miles.

VIEWS
The spotlight of environmental concerns invariably encompass the world of aviation, an industry perceived as a major contributor in aggravating the problems connected with carbon dioxide (CO₂) and nitrogen oxide (NO_X) emissions – namely, global warming. While the jury is still out on the validity of that allegation, in air transportation, perception has inexplicably scored over hard facts – not surprising given the sector’s high visibility which fans such illusory and preconceived notions. However, these misconceptions have also come as a boon in disguise fuelling the entire aviation industry’s desire for continuously taking on the challenges of reducing greenhouse gases with the utmost sincerity it deserves.

Boeing’s SUGAR Volt concept is the outcome of one such attempt initiated by the National Aeronautics and Space Administration (NASA) to develop environmental and performance concepts that will help guide the agency’s aeronautics research over the next 25 years. Known as N+3 to denote three generations beyond today’s commercial transport fleet, the research programme is aimed at identifying key technologies, such as advanced airframe configurations and propulsion systems that will enable greener airplanes to take flight around 2035.

NASA selected six US teams that won contracts in 2008 to undertake conceptual studies for both subsonic and supersonic air travel. Four teams—led by Boeing, GE Aviation, Northrop Grumman and MIT, respectively—studied concepts for subsonic commercial aviation. The objective was to develop the concepts and evaluate the potential of quieter commercial airplanes that would burn 70 per cent less fuel and emit 75 per cent less NOX than today’s commercial airplanes. It was apparent that NASA’s aggressive criteria would require ‘radical’ change in the design of airframes and propulsion systems.

The two outstanding teams—one led by MIT and the other by Boeing—appeared to have followed different routes to achieve design objectives. The MIT team met NASA’s challenges by developing two designs—the 180-passenger D ‘double bubble’ series and the bigger 350-passenger H ‘hybrid wing body’ by introducing major reconfigurations in airframe design. The engines though conventional have been shifted to the rear of the fuselage which permits them to take slower moving air from the plan’s wake, also known as boundary layer ingestion (BLI), resulting in less fuel burn while producing the same amount of thrust, but the penalty is greater stress on engines.