Grumman G-21A Goose

The Grumman G-21 Goose (universally celebrated across maritime aviation history and simulator hangars as the G-21A, Grumman Goose, Turbo Goose, and ddenn Goose) is one of the most versatile amphibious flying boats ever conceived. Designed in 1937 by Leroy Grumman as an eight-seat "flying yacht" for Long Island businessmen commuting to Manhattan, the aircraft quickly proved its rugged utility in World War II with the US Navy, RAF, and Coast Guard before serving as the lifeline of coastal Alaskan and Pacific island bush flying. Originally created as a revered commercial payware add-on by master 3D artist Denis Krupin (ddenn), the project was acquired by X-Plane.org and completely upgraded for X-Plane 12, featuring backend SASL 3.0 systems programming by Sofia of the FlightFactor team.

The package includes three distinct airframe and propulsion configurations: the Classic Goose (dual 450-hp Pratt & Whitney R-985 Wasp Junior radial engines with fixed wingtip floats), the Retractable Floats Goose (featuring motorized wingtip sponsons that retract flush into the wings during cruise flight), and the Turbo Goose (modernized conversion equipped with dual Pratt & Whitney Canada PT6A turboprop engines and flat-rated beta-range reverse thrust). The cockpit delivers a vintage maritime ambiance with authentic analog gauges, operable overhead switch panels, functional cabin doors, and interactive 2D/3D pop-up control panels that allow pilots to manage ground servicing, mooring lines, and animations from any camera view.

In the X-Plane 12 flight environment, the Grumman Goose shines on water and land alike. Taking off from choppy coastal waters requires authentic seaplane airmanship: Virtual pilots must manage step-taxiing attitude, deploy the water rudders for slow maneuvering in harbor currents, and retract them before accelerating through the spray. On hard runways, the conventional taildragger layout demands careful rudder pedal coordination to maintain directional stability. Powered by SASL 3.0, systems modeling accurately replicates dual engine start flows, hydraulic landing gear hand-cranking backups, and flap actuation. Released completely free of charge to X-Plane.org members, the ddenn Goose stands as one of the most generous and well-crafted freeware amphibian additions available for XP12.

Primary Missions & Operational Roles

• Coastal Alaskan & Fjords Bush Flying: Delivering passengers, mail, and cargo into remote logging camps, coastal bays, and sheltered glacier inlets across Alaska, British Columbia, and Scandinavia.

• Island-Hopping Harbor-to-Harbor Commutes: Operating scheduled visual commuter hops between coastal ocean ports, seaplane bases, and small municipal airfields (recreating vintage Catalina Flying Boats or PenAir island runs).

• Radial vs. Turboprop Multi-Engine Transition: Comparing the operational handling of classic twin Pratt & Whitney R-985 round engines against the high-altitude climb performance and beta-range reverse thrust of the PT6A Turbo Goose.

• Seaplane Rating & Water Landing Mastery: Mastering hydrodynamic step taxiing, water-loop prevention, glassy-water landing techniques, and beaching operations using retractable amphibious landing gear.