The Envoy originated as a heavier twin-engine derivative of Airspeed's Courier light transport aircraft. Sharing much of its design with this earlier aircraft, it was relatively easy to develop; confidence in the project was so high that within a week of the prototype's maiden flight, it was performing as a display aircraft to the public. Quantity production of the Envoy had been initiated even before this first flight. Early on, Airspeed worked closely with the British engine manufacturer Wolseley Motors as both a key supplier and early custom of the Envoy; development subsequently branched out to a wide variety of engines and configurations.