As winter continues its merciless hold on most of the country, many pilots are starting to plan their 2020 airshow season, including a trip to the SUN ‘n FUN Aerospace Expo, known as the official kick-off to the season.

A precursor to the SUN ‘n FUN activities is Seaplane-A-Palooza, traditionally held the weekend before SUN ‘n FUN in Tavares, Florida, which is known as the Seaplane City.

One of the biggest hits at last year’s Seaplane-A-Palooza — and SUN ‘n FUN — was the Gweduck Flying Boat, an amphibian inspired by the 1940s Grumman Widgeon.

In late 2019, the first kit was sold. That’s a milestone for the project, which began in 1990 when Gweduck lead designer Ben Ellison and Ross Mahon saw a Widgeon taxi by at their home airport in Renton, Washington, near Seattle.

Gweduck designer and owner Ben Ellison, Jim Schoeggl, who helped build the plane, and Walter Fellows of Composite Creations, at SUN ‘n FUN 2019. (Photo by Joni M. Fisher)

Ellison, who invented the Ellison Throttle Body for aircraft engines and ran that business for 34 years, had planned to buy a Widgeon to replace the deHavilland Beaver on floats he used to commute from Seattle to his boat, which was moored at Roche Harbor in the San Juan Islands.

However, he soon realized that an aluminum airplane operating in salt water would literally “dissolve” over time due to corrosion. Also, if not carefully controlled, the Widgeon has a tendency to porpoise during water landings, a trait that has led to serious accidents.

Composite construction was the obvious answer to the corrosion problem, but rather than just build a fiberglass copy of the Widgeon, Ellison and Mahon did extensive research and soon realized they did not know enough about flying boats.

Their timing was good, however, since numerous Boeing retirees live in the Seattle area and the early 1990s offered one of the last opportunities to tap the expertise of flying boat designers and pilots who had experience with the Boeing 314 “China Clipper” and Grumman amphibians.

“The design stage took a decade and Bryan Mahon, Ross Mahon’s father, was one of our greatest resources of information,” explained Ellison. “Bryan was with Boeing and headed production of the PBY Catalina in Vancouver, BC, during World War II.”

They also consulted David Thurston, a former Grumman engineer who designed the Skimmer amphibian, which later became the Lake Buccaneer.

“The advent of the Internet provided a rich resource of information from NACA reports,” added Ellison.

“Together, we put together a matrix of the flying characteristics of the better-known amphibians, both good and bad,” he said. “We then worked to keep the good characteristics and avoid all the others.”

When it became obvious that the Widgeon’s hull design needed to be completely changed, an 11′ radio-controlled quarter-scale model was fabricated and powered with two chainsaw engines.

Interchangeable “slippers” made it possible to change hull designs easily and to quickly prove what worked best, according to Ellison.

“The well-known Widgeon porpoising problem was duplicated first and we kept fine-tuning the model until we had an extremely benign hull shape,” he said.

Next came the problem of controlling prop spray during takeoff. The solution came from examining photos of the Japanese Shin-Meiwa flying boat, which has “ducts” running along both sides of the hull to capture and control the spray.

Counter-rotating 300-horsepower Lycoming IO-540 engines were chosen to power the six-passenger plane. The MT propellers have flat-pitch, feathering and reversing capabilities. To allow docking, the two wing tip floats are retractable.

After years of flights around the Northwest, summer trips to Alaska, and appearances at SUN ‘n FUN, EAA AirVenture Oshkosh, and other airshows, the prototype is a proven performer with 1,200 flight hours.

“We can fly from Seattle to Sitka non-stop in around five and a half hours and we love flying along the coast of Alaska at 500′,” said Ellison with the satisfied look of a man whose dream has come true through hard work and perseverance. He was 50 when he started the Gweduck project. He’s now 79.

Walter Fellows, a retired investment banker from Seattle, has joined the Gweduck team to carry the project forward. His company, Composite Creations of Prineville, Oregon, licensed the design and is bringing the plane to market as a kit.

Based on experience gained through working for many years at Lancair in nearby Bend, Oregon, the staff of Composite Creations has a long history of fabricating airframes and other components from carbon fiber.

“We’ve made very few changes to the design as we’ve developed the kit,” said Fellows.

With an estimated completed price tag of around $1 million, depending on options selected, the big amphibian represents a substantial investment. However, Fellows expects small ownership groups to band together and share a Gweduck.

Also, Fellows reports “strong interest” in the design from foreign governments. He adds certification is possible at a much later date.

What’s a Gweduck?

First of all, it’s pronounced “Gooey Duck.”

Secondly, if you think it’s the name of another waterfowl like the Widgeon or Goose, you’ve got another surprise coming.

Although it might sound like an exotic bird, the name is somewhat of an inside joke because a Gweduck is actually a clam-like bivalve common in the Northwest that buries itself in the mud at low tide.

So, with all the good waterfowl names already taken by other amphibian aircraft, Gweduck it is.