Helio STOL Experimental
Helio was founded 1948 as Helio Aircraft Corporation to develop the two-seat Koppen-Bollinger lightplane. Otto Koppen may best be known as the creator of the Helio, the first modern short-takeoff airplane. "We built the Helio before STOL was invented," Koppen remembers. "I felt that an effective short-field airplane shouldn't have to fly at the obstacle, it should be able to fly around it." Koppen wanted an airplane that could climb steeply and maneuver safely at low airspeeds and high angles of attack.