 In the early 1970s, Aspen began operating Convair 580 turboprop aircraft.The twin engine CV-580 propjet became the workhorse of the Aspen fleet.Other aircraft operated by Aspen Airways in the 1960s included a Fairchild F-27 turboprop (which didn't work out very well in the high density altitude conditions that can occur at high elevation mountain airfields), and piston and turboprop variants of the de Havilland Heron as well as Piper Navajo and Aero Commander 500B aircraft.