Hovering not hard if you're top-heavy, researchers find

Top-heavy structures are more likely to maintain their balance while hovering in the air than are those that bear a lower center of gravity, researchers at New York University's Courant Institute of Mathematical Sciences and Department of Physics have found. Their findings, which appear in the journal Physical Review Letters, are counter to common perceptions that flight stability can be achieved only through a relatively even distribution of weight—and may offer new design principles for hovering aircraft.