EAS IX: Low Aspect Ratio Airplanes – Against the Grain

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Barnaby Wainfan is a technical fellow with Northrop-Grumman, but possibly best known for the FMX-4, well known as the “Facetmobile.”   His talk on “Low Aspect Ratio Electric Airplanes gave attendees at the ninth annual Electric Aircraft Symposium a great deal of counter-intuitive insights into how a successful airplane can look and work. The FMX-4, he pointed out, is a low-aspect-ratio, light weight, single primary structure, low-parts-count airplane with benign flying qualities.  When, as he told his audience, he decided to stop talking and start testing, he began with X-Plane computer simulations to check out his theories and studied simple, fast-building structures that would get him into the air expeditiously. N117W was easier to build than curved sticks, and despite its angular lines, the airflow doesn’t separate over its flat surfaces.  He could carry an approach at 10 degrees positive angle of attack (AOA) and still have 30 degrees available before reaching a stalling point. The airplane carries a payload equal …