It first flew on August 14, 1958. After first rejecting an idea to develop the Grumman Widgeon as an executive transport, the company studied producing an executive transport based on a turbine-powered variant of the naval utility transport Grumman TF-1 Trader. The company had already determined that any new aircraft would have to be turboprop-powered and the Rolls-Royce Dart engine was chosen. Further studies showed that the Trader-based design would not sell and they needed an all-new design with a low-wing and room to stand up in the cabin. In June 1957 the design of G-159 was finalised. The Gulfstream I is a low-wing cantilever monoplane with a semi-monocoque aluminium alloy fuselage structure. The aircraft is powered by two Rolls-Royce Dart turboprops with Rotol four-bladed constant speed propellers. The Gulfstream I has a retractable tricycle landing gear, with twin wheels on the two main units and the nose gear. The cabin is designed to take up to twenty-four passengers in a high-density arrangement or only eight in an executive layout, although ten to twelve was more usual. The aircraft has a hydraulically operated airstair in the forward cabin for entry and exit. In Austrtalia, Executive Airlines operated a G-159 based at Essendon. For more details of the development operational history and variants of the G-159, click here.