Burt Rutan developing new seaplane

April 9, 2013

Two years after retirement, Burt Rutan is at it again, developing a new seaplane called the Skigull at his cabin near Coeur d’Alene, Idaho. At first he thought he had an original design, a tandem-seat twin-engine amphibian that rises from the water on skis but can land on snow, grass, and if you must, a paved airport. Then he found the 1950s Sea Dart on the Internet. You can see a video of the Sea Dart test flights here.

The Skigull is also a motorglider. It has to be if Rutan, who lost his medical in 1998, is going to fly it. An FAA friend told him that he needed longer wings if he wanted it to qualify as a motorglider. The definition indicates the maximum weight-to-wing-span-squared must not exceed three kilograms per square meter. So Rutan created a 43-foot wingspan that can be folded for docking, while still on the water, or for storage in a garage. The design may be sold as a kit, “…if it works,” Rutan told a meeting of The Old Bold Pilots in California in January.

A video of that talk can be seen on YouTube. His explanation of the Skigull starts at minute 38. You’ll notice the camera moves around the screen so as not to show the design, per Rutan’s wishes. It was posted by The Old Bold Pilots on Feb. 1. You can see more of the group’s videos here.

If it works, Rutan will have himself a tiny amphib capable of making it from the cabin to Oshkosh with one stop. He won’t need a medical. He has not chosen the engines because he does not yet know the power that will be needed, but they can be as little as 50 to 70 horsepower. Those two engines will blow across a high-lift section of the wing. With all that wingspan comes the tendency to float, so he will have big flaps to give him short takeoff and landing capability for small lakes—the kind he likes to explore.

When you must positively, absolutely land at a boring paved airport, roller-blade wheels will extend three-tenths of an inch below the skis. The skis are coated with the same kind of plastic used on recreational skis and Iditarod race sleds in Alaska.

The airplane is a trimaran, with 40 percent of its weight supported by the sponsons and 60 percent supported by the hull. The pilot’s waist will be below the waterline. There are still questions to be answered, so a wooden model of the Skigull has been completed and will be attached to an old beater boat that will push it through the water to measure the power required. Designing the boat has given Rutan fits.

During a question-and-answer session Rutan also noted his old company, Scaled Composites, is building the biggest airplane in the world to carry a spacecraft aloft for launch. It is built by Stratolaunch Systems and is known inside the factory as Roc after a mythical bird that could carry an elephant. He spent 21 years designing it, but left before it was funded. It will be housed in a new hangar with the widest hangar door in the world, Rutan said. NASA had the tallest hangar doors with its Vehicle Assembly Building at Kennedy Space Center, but Scaled Composites has the widest at 430 feet.

He also urged the aviation industry not to defend aircraft designs, but to question them constantly as a method of improving them. Defending what may be a flawed design is no way to treat customers, he said.