The Grumman G-21 Goose is an amphibious flying boat designed by Grumman to serve as an eight-seat "commuter" aircraft for businessmen in the Long Island area. The Goose was Grumman's first monoplane to fly, its first twin-engined aircraft, and its first aircraft to enter commercial airline service. During World War II, the Goose became an effective transport for the US military (including the United States Coast Guard), as well as serving with many other air forces. During hostilities, the Goose took on an increasing number of combat and training roles.

Design and development

In 1936, a group of wealthy residents of Long Island, including E. Roland Harriman, approached Grumman and commissioned an aircraft that they could use to fly to New York City. In response, the Grumman Model G-21 was designed as a light amphibious transport. Grumman produced a high-wing monoplane of almost all-metal construction—the trailing half of the main wing and all of the flight control surfaces except for the flaps were fabric-covered. It was powered by two 450 hp Pratt & Whitney R-985 Wasp Junior nine-cylinder, air-cooled, radial engines mounted on the leading edges of the wings. The deep fuselage served also as a hull and was equipped with hand-cranked retractable landing gear. First flight of the prototype took place on May 29, 1937. The fuselage also proved versatile, as it provided generous interior space that allowed fitting for either a transport or luxury airliner role. Having an amphibious configuration also allowed the G-21 to go just about anywhere, and plans were made to market it as an amphibian airliner.

Modifications

A number of modifications were made for the Goose, but the most numerous are those by McKinnon Enterprises of Sandy, Oregon, which holds 21 supplemental type certificates (STCs) for modifying G-21-series aircraft and which also manufactured four different conversions that were recertified under a separate FAA type certificate as brand-new "McKinnon" airplanes. The first was the McKinnon model G-21C which involved replacing the original R-985 radial engines with four Lycoming GSO-480-B2D6 piston engines. It was approved under TC 4A24 on November 7, 1958, and two examples were converted in 1958–1959.

New production

In November 2007, Antilles Seaplanes of Gibsonville, North Carolina, announced it was restarting production of the turbine-powered McKinnon G-21G Turbo Goose variant, now identified as the Antilles G-21G Super Goose. Pratt & Whitney Canada PT6A-34 turboprops flat-rated to 680 shp would have replaced the original PT6A-27 engines, and the airframe systems and especially the avionics (aviation electronics – i.e. radios and navigation systems) would have been updated with state-of-the-art "glass panel" instrumentation and cockpit displays. However, as of 2009, Antilles Seaplanes' manufacturing center has been foreclosed and sold at auction. The fate of new Goose production is currently unknown.

Operational history

Envisioned as corporate or private flying yachts for Manhattan millionaires, initial production models normally carried two to three passengers and had a bar and small toilet installed. In addition to being marketed to small air carriers, the G-21 was also promoted as a military transport. In 1938, the U.S. Army Air Corps purchased the type as the OA-9 (later, in the war years, examples impressed from civilian ownership were designated the OA-13A). The most numerous of the military versions were the United States Navy variants, designated the JRF. The amphibious aircraft was also adopted by the Coast Guard and, during World War II, served with the Royal Canadian Air Force in the transport, reconnaissance, rescue, and training roles. The G-21 was used for air-sea rescue duties by the Fleet Air Arm, who assigned the name Goose. A single aircraft was used briefly by No. 1 Air Ambulance Unit, Royal Australian Air Force in the Mediterranean.[21] After the war, the Goose found continued commercial use in locations from Alaska to Catalina and the Caribbean. A total of 345 were built, with about 30 known to still be airworthy today (although around 60 are still on various civil registries, many of them are known to have crashed or been otherwise destroyed), most being in private ownership, some of them operating in modified forms.

Variants

Operators

Military operators

Civil Government operators

Civil operators

Accidents and incidents

Aircraft on display

Specifications (JRF-5 Goose)

Notable appearances in media