Mace-Trefethen R-2The Mace-Trefethen R-2 Shark is an American single place racing aircraft designed in the 1970s.Design and developmentThe R-2 is a single seat, low-wing aircraft with conventional landing gear. The wooden construction aircraft features an elliptical wing.Operational historyAt the 1970 Reno Air Races Mace achieved a speed of