PlaneFox tracks 1 G-21 Goose aircraft for sale and re-reads every one of them from the broker and dealer sites it watches, so the figures below move when the market moves. Every number on this page is measured from those live listings, not taken from a published price guide.
The Grumman / Grumman American G-21 Goose is a twin engine amphibian originally developed by Grumman as a private executive transport and utility aircraft. It first flew in 1937, with production running into the mid 1940s. The type later served widely in military, coastal patrol, commuter, cargo, survey and lodge support roles. Its importance comes from its combination of boat hull, retractable landing gear and robust radial engine layout, giving buyers access to both water and conventional runways in a vintage transport category.
Most standard G-21A aircraft use two Pratt & Whitney R-985 Wasp Junior radial engines, each rated at 450 hp. Typical cruise planning is commonly in the 120 to 135 knot range, depending on engine condition, propellers, weight, rigging and whether the aircraft has original or modified equipment. Published range figures are generally around 550 to 640 nautical miles for standard aircraft. Maximum takeoff weight is commonly listed at 8,000 lb, with useful load varying by individual airframe and modification status. The service ceiling is published at about 21,000 feet, although practical operations are usually far lower, especially in seaplane service.
The Goose typically carries two pilots and up to six or seven passengers, depending on interior layout, baggage arrangement and certification basis. The cabin is compact by modern turboprop standards but unusually practical for water access, with a hull configuration suited to mixed passenger, cargo and field support missions. Avionics vary substantially. Many examples retain a traditional analog panel with later navigation and communication upgrades. Common modern fits may include Garmin GNS or GTN navigators, ADS-B equipment, audio panel upgrades, transponder replacements and engine monitoring systems. Integrated suites such as Garmin G1000 or Garmin Perspective are not typical for the G-21 Goose.
Prospective buyers should evaluate the Goose as a specialized vintage amphibian, not as a conventional light twin. Key inspection areas include hull corrosion, saltwater exposure history, bilge and keel repairs, wing and float attach points, retractable landing gear, control cables, fuel system condition and documentation for past structural work. Engine logbooks, R-985 overhaul status and propeller condition have a major effect on operating cost. Common market references include the civil G-21A, military JRF derivatives and McKinnon conversions, including piston and turboprop modified aircraft. Values are highly condition driven, with premium examples generally distinguished by documented restorations, clean corrosion history, modern radios and proven water operating capability.