‘Gweduck’ Makes First Flights
Amphibian aiming for AirVenture
May 7, 2009 — An airplane that has generated a lot of interest in the seaplane community, the Gweduck flying-boat style amphibian, has made its first flights off the water on Lake Washington in Renton, Wash. Land-based flights are expected to take place this weekend, and hopefully the twin-engine high wing will be flown to Oshkosh for EAA AirVenture 2009 this summer.
The Gweduck (pronounced "Gooey-Duck") was designed by Ben Ellison, EAA 72406, owner of Ellison Throttle Body Injectors (www.Ellison-TBI.com) and is a ground-up redesign of a Grumman concept. It’s made of composite materials, seats two pilots and four passengers, and according to Ross Mahon, EAA 215408, one of the test pilots and builder.
“It was originally designed in the early 1990s as a composite Widgeon,” he said. According to the project website, the idea behind building such an aircraft was to “eliminate the extensive corrosion and maintenance problems so common to the 40+-year-old design.” That evolved into a ground-up redesign of a completely new aircraft combining 1940s and 1950s flying boat designs with modern composite construction, as well as the latest in aerodynamic and hydrodynamic technologies.
The airplane’s name derives from the name of a large clam indigenous to the Pacific Northwest called the geoduck (which is pronounced “gooey duck.”)
Mahon said by bringing the airplane to Oshkosh they would get a feel of what the interest is. Depending on the reaction, it’s possible they may begin marketing an aircraft kit. The actual display area has yet to be determined, but flight demos are planned for the Seaplane Base.
The team is confident this weekend’s flights off Renton Municipal (adjacent to Boeing’s Renton operations, where 737s are made) will be successful. “Based on the high-speed taxi tests and the flights last week, we don’t expect any issues,” Mahon said.
Last weekend’s half-dozen flights on Lake Washington, piloted by former Boeing test pilot Buzz Nelson, included flap position changes, retracting the wing tip floats, and generally exploring the flight envelope. Altitude reached was about 3,000 feet MSL. “Water takeoff and landing behavior was excellent,” Mahon said.
Length: 32.5 ft
Height: 10.8 ft
Wing span: Tip Float down 48 ft
Wing area: 295 sq. ft.
Wing loading: 20.3 Lb/sq. ft.
Power loading: 10.3 Lb/sq. ft.
Seats: 2 pilots, 4 passengers
Cabin width: 54”
Engines (2): Lycoming, IO-540 & LIO-540
Propeller: MT Propeller, 3 Blade, constant speed, feathering, reversing.
Design Gross Weight: 6000 Lbs
Useful load (Typical): 1800 Lbs
Fuel capacity (Each side): Inboards tanks 40 Gals./Outboard tanks 60 Gals.
Estimated Performance: Cruise Speed - 135 Knots at 65% power at 3000 ft MSL