The Seawind is a family of composite, four-seat, amphibian airplanes that all feature a single tail-mounted engine. They have been produced as kits and were at one time under development to be sold as completed aircraft.
The Seawind design originated in Canada, where the prototype flew for the first time on 23 August 1982. Later development and production was carried out by Seawind International of Haliburton, Ontario, Canada, before the rights were acquired by SNA and production moved to Kimberton, Pennsylvania, United States. The major production versions of the Seawind line consist of the kit-built Seawind 2000 and Seawind 3000 and the Seawind 300C that was under development by Seawind LLC, also of Kimberton, Pennsylvania. The Seawind 3000 was introduced in 1993.
Production of Seawind 3000 kits was suspended in 2002 to concentrate on certification of the 300C and the kits are no longer available.
The Seawind 300C was intended to be the certified production version, derived from the kit-built Seawind 3000. It incorporated many changes required to conform to the certification standards. The company indicated that certification flight testing would continue after the crash of the prototype on August 16, 2007, but did not actually resume until early 2010. Certification flight testing continued through the summer and autumn of 2011, but by the end of 2020 the company website had been taken down and the company seems to have ceased business.
Design
The Seawind is most distinctive for its engine pod, which juts forward from the leading edge of the very large vertical fin. The design is also noted for its long, low profile and sleek curves made practical by composite construction.
The Seawind is relatively quiet for the crew, primarily because the engine is above and behind the cabin and the exhaust is routed up and aft. Some amphibian aircraft use a pusher propeller arrangement, which causes the exhaust to pass through the propeller plane which can increase noise. The Seawind uses a conventional tractor propeller arrangement that avoids this issue.
The cabin is very wide for an airplane of this type and seats 4 adults. A factory option replaces the aft executive bucket seats with seating for 3 children. The wide cabin also supports a large instrument panel, allowing installation of virtually any avionics.
There are three cargo compartments: under the nose deck ahead of the canopy, behind the rear seats in the cabin, and the tailcone.
The wing uses a constant-chord NASA NLF airfoil drooped at the ends. The wingtips provide some endplate effect to increase ground effect and reduce induced drag. They also serve as wingtip floats. The wing has a reflexed (negative angle of attack) trailing edge to reduce drag at cruise.
The Seawind 2000 and 3000's retractable landing gear is hinged to the side of the hull and folds up into the wing for flight and water operations. The certified landing gear is a trailing link-type, fully mounted in the wing.
An electric/hydraulic powerpack provides hydraulic power for the flaps, landing gear and nose-wheel steering. The hydraulic pack and battery are located in the nose compartment.
Fuel is gravity fed from the main tanks to a header tank to supply the engine. Optional long range tanks in the wing tips have electric pumps to transfer fuel to the main tanks. Fuel can also be pumped from side to side to correct any lateral imbalance.
Steering on land is provided by differential braking. Hydraulic nose-wheel steering is available as an option. A retractable water rudder is slaved to the air rudder for water operation.
Development
The Seawind was originally designed in the late seventies in Haliburton, Ontario. Seawind kits were developed and sold by SNA Inc. of Kimberton, Pennsylvania, United States. Seawind LLC was formed to certify the Seawind design as a complete aircraft and market it as the Seawind 300C. The Seawind 300C factory is located in Saint-Jean-sur-Richelieu, Quebec, Canada.
Seawind 2000
The Seawind 2000 was the first kit prototype, powered by a Lycoming IO-360 engine. Although top and cruise speeds were respectable, SNA felt that the aircraft needed more power. A engine was installed, as well as several modifications, to create the Seawind 3000.
Seawind 3000
In addition to the larger engine, the Seawind 3000 had changes to the hull and step configuration. The Seawind 2000 canopy was hinged to allow opening from either side while the 3000 was hinged to open at the back.