The Grumman Gulfstream I (company designation G-159) is a twin-turboprop business aircraft. It first flew on August 14, 1958. Design and development 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 and Grumman started selling slots on the production line at $10,000 each. The initial customers worked with Grumman on the detailed design and avionics fit. The G-159 was given the name Gulfstream and on 14 August 1958 the first aircraft, registered N701G, took off from Bethpage, New York on its maiden flight. By 2 May 1959 the aircraft was awarded a type certificate by the Federal Aviation Administration (FAA). 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. The United States military version for this plane is the C-4 Academe. The TC-4 is a version with added instruments and navigation. It was used by the US Navy for bombardier/navigator training for the A-6 Intruder. A VC-4A variant was flown by the United States Coast Guard as an executive transport until the early 1980s. It was later used as a logistics and long-range command and control aircraft until 2001. A 37-passenger stretched version, the G-159C, was developed by Gulfstream for regional airline use. Five were delivered from November 1980. Air North (based in Plattsburgh NY and which subsequently changed its name to Brockway Air) was one of the few airlines in the U.S. to use this version before its acquisition by Brockway Glass.