While AeroVironment’s Global Observer High Altitude Long Endurance aircraft has flown at the NASA Dryden Flight Test Center, Boeing’s PhantomEye HALE is in pieces but undergoing testing prior to being shipped to Dryden. PhantomEye’s hydrogen-fueled engines are being tested at Santa Clarita, California and airframe parts are being prepared for flight at Boeing’s St. Louis, Missouri plant. AeroVironment’s craft has now flown with fuel cells providing electricity to run the four wing-mounted motors. PhantomEye uses hydrogen stored in eight-foot diameter tanks in its fuselage to directly fuel the twin Ford 2.3-liter modified engines. At altitude, a three-stage turbocharger will be required to provide air for an efficient fuel burn. Both unmanned aerial vehicles have similar missions, to fly at 65,000 feet for up to a week at a time while providing surveillance, monitoring, and communication for military and civilian applications.
A Sweet Look Into the Future
Zach Hoisington, an engineer with Boeing Research and Development, proposes an electric airliner concept through the Subsonic Ultra Green Aircraft Research (SUGAR) program. During the CAFE Foundation’s fourth annual Electric Aircraft Symposium in Rohnert Park, California in April this year, he shared an amazing array of alternatives. Making airliners viable in an era of disappearing fossil fuel has caused NASA and aircraft producers to explore different design approaches, including joined wing aircraft, strut-braced wings, and hybrid wing-body configurations. Strategies for doing more with less may include aerial refueling for extended range flight with larger payloads, and formation flights on common routes like those of migrating birds to reduce induced drag. New sources of power may include hydrogen fuel cells and podded or integral batteries. Although the last option filled most of the talk, it came with the caveat that given current levels of battery development, it would take 5.5 million pounds of cells to produce the same energy derived from 60,200 pounds of …