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  Aircraft History, Specification and Information
Seawind
Seawind 3000 - C-GAKA - Amphibian Airplane
Seawind 3000 - C-GAKA (sn 46)
Photo taken Mar. 13, 2005
Penticton, BC - Canada (YYF / CYYF)
Photo © Marcel Siegenthaler

The Seawinds are a family of composite, four-seat, amphibian airplanes that all feature a single tail-mounted engine.

The Seawind line consists of the kit-built Seawind 2000 and Seawind 3000 that were marketed by SNA Inc. of Kimberton, Pennsylvania, USA and the Seawind 300C that was developed by Seawind LLC, also of Kimberton, Pennsylvania. The Seawind 3000 was introduced in 1993.

The Seawind 300C was intended to be the certified production version of the kit-built Seawind 3000. The company indicated that certification flight testing would continue after the crash of the prototype on August 16, 2007, but did not actually continue until early 2010.

Production of Seawind 2000 and 3000 kits was completed in 2004 to concentrate on certification of the 300C and the kits are no longer available.

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 back. 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 relatively large propeller also keeps propeller speed below 2500 rpm to further reduce noise.

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 a bench to provide 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.

Retractable landing gear is hinged to the side of hull and folds up into the wing for flight and water operations.

An electric/hydraulic powerpack provides hydraulic power for the flaps, landing gear and optional nose-wheel steering. The hydraulic pack and battery are located in the nose compartment.

Fuel is gravity fed from the main tanks to a standpipe to supply the engine. Optional auxiliary 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 early 1980s in Canada. Seawind kits were developed and sold by SNA Inc. of Kimberton, Pennsylvania, USA. Seawind LLC was formed to certify the Seawind design as a complete aircraft and market it as the Seawind 300C. The Seawind 300C factory was to be located in Saint-Jean-sur-Richelieu, Quebec, Canada.

Seawind 2000

The Seawind 2000 was the first kit prototype, powered by a 200 hp (149 kW) Lycoming IO-360 engine. Although top and cruise speeds were respectable, SNA felt that the aircraft needed more power. A 300 hp (224 kW) 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.

The Seawind 3000 first flew in late March 1993. The first prototype crashed during testing on 3 April 1993 with test pilot Bob Mills and SNA president Dick Silva onboard. After several routine tests, they attempted to simulate an engine-out situation reducing the engine power and setting the prop pitch to high. However, due to a malfunction, the propeller went into flat (or possibly reverse) pitch. This caused excessive drag and prevented the propeller from windmilling. The crew attempted to reach the runway but, due to the high descent rate and lack of power, they landed in rough terrain short of the runway at approximately 80 mph (129 km/h), hitting several boulders on two sides of an embankment. The crash forces were estimated to be in excess of 15Gs. Although the aircraft suffered extensive damage, both crew suffered only muscle strains. The crash also showed the strength of the composite structure and, in particular, the vertical fin/engine pylon arrangement. Some skeptics had felt this was a potential weak point in the Seawind design, although the pylon is capable of 15G vertical and 20G forward loading, more than twice the certification requirement.

The prototype was rebuilt with a non-reversible constant speed propeller and testing resumed in December 1993.

SNA estimated that it would take the average builder 2000 hours to complete a Seawind 3000 kit. A "Kwick Kit" option was also available, which provided some of the major components pre-assembled to reduce the build time to approximately 1500 hours.

A standard kit was $59,900 USD in 1999. A Kwick Kit cost an extra $14,500 USD. SNA estimated that it would cost $40,000-65,000 USD for the necessary components not included with the kit. A fully assembled Seawind kit with instruments typically cost over $200,000 USD.

The first customer built Seawind 3000 was completed in mid 1994.

Seawind 300C

The Seawind 300C was developed from the 3000 and incorporated many changes needed to conform to the Canadian CAR 523 standards. Flight testing was commenced in Canada as the aircraft was intended to be manufactured at the plant at Saint-Jean-sur-Richelieu, Quebec. Certification in the USA under FAR 23 was to have followed Canadian certification.

The 300C was undergoing certification testing when the prototype crashed near Winnipeg, Manitoba, on August 16, 2007 killing test pilot Glenn Ralph Holmes. At the time of the accident, the company indicated it would shut down, but in October 2007 stated that test flying would continue once additional personnel were hired and additional funding secured.

In July 2008 the company announced that was still pursuing certification and commencement of production, a task it stated would require USD$4 million.

In September 2008 the company announced that it had raised $1.2 million but required $800,000 to recall employees to work. The company indicated that it had two Seawind prototypes available which could be used to complete the certification flight test program. Regarding the timeline to restart the flight testing and production, company president Dick Silva stated in September 2008, "There is a limit to how long we can go without resuming the project. Time is our enemy."

In April 2009 Silva announced that the company had found sufficient funding to restart, would rehire staff and intended to have a replacement prototype ready to fly by the beginning of August 2009, with the aim of completing the certification of the 300C. The company also stated that investigation into the crash of the prototype ruled out in-flight failures or other problems with the aircraft.

The August 2009 date to recommence flight testing was not met and the aircraft was then forecast to start flight testing by contract National Research Council test pilots in February 2010, though this date was not met either. In early March 2010, Seawind announced the rollout of the test aircraft and the imminent start of taxi tests. The Seawind finally flew again later that month and was transferred to the NRC facility in Ottawa. Silva publicly announced that certification would be complete in June 2010 and that he was seeking funding for the stages beyond that, including production. By September 2010 the flight testing had just commenced with re-instrumentation and solving a landing gear door flutter issue. By the end of 2010 certification flight testing had identified two problem areas, loss of rudder effectiveness in power-off spins and lack of flap effectiveness. The former problem was to be addressed with stick shaker and stick pusher systems, labeled the Stall Prevention System, and the latter with revised flap hinge geometry to achieve a more effective slot. Flight testing continued in the spring of 2011 with testing for flutter as well as damage tolerance and fatigue testing was completed. Following will be testing of the Stall Prevention System and water testing.

In April 2011 the company announced that it had 50 Seawind 300C orders, that the final design configuration was frozen as a result of progress in the certification test flying and that the company only lacks funding to start building pre-production aircraft. The final design will now include a "stall prevention system" that will prevent the aircraft from stalling or spinning. By June 2011 the company still confirmed that they had 50 orders.

Certification flight testing continued though the summer and autumn of 2011 with fixes for problems with adverse yaw, lateral stability, ineffective rudder trim at low power settings, pitch damping, roll/yaw damping, high rotation forces on takeoff and the stall prevention system. The aircraft had still not conducted water trials. Of the certification process the Flight Analyst Designated Airworthiness Representative, John Taylor, said "It should be recognized that the Seawind has a very unconventional configuration and as a consequence, has at times been a very challenging configuration to make compliant with FAR Part 23 certification requirements."

Operational history

In September 2007 there were 13 Seawind 2000 and 3000 amateur-builts registered in Canada and 58 in the USA. Due to kits purchased some time ago being completed, this number is expected to increase over the next few years, minus any aircraft destroyed in accidents.

Specifications (300C)

General characteristics
Crew: 1 pilot
Capacity: 3 adult passengers or 1 adult passenger and 3 children
Length: 27 ft 2 in (8.28 m)
Wingspan: 35 ft 0 in (10.67 m)
Height: 10 ft 2 in (3.10 m)
Wing area: 163 ft² (15.14 m²)
Airfoil: NLF(1)-0215(F)
Empty weight: 2,300 lb (1,043 kg)
Useful load: 1,100 lb (499 kg)
Max. takeoff weight: 3,400 lb (1,542 kg)
Powerplant: 1 × Continental IO-550-N Flat 6 piston engine, 310 hp (231 kW)
Propellers: 1, McCauley 3-blade Constant Speed propeller
Propeller diameter: 76 in (1.93 m)

Performance
Maximum speed: 174 knots (200 mph, 322 km/h) at sea level
Cruise speed: 147 knots (169 mph, 272 km/h) at 55% power at 8,000 ft (2438 m)
Stall speed: 63 knots (72 mph, 116 km/h) in clean configuration
Range: 905 nm (1040 mi, 1674 km) with main tanks
Service ceiling: 18,000 ft (5,486 m)
Rate of climb: 1250 ft/min (6.35 m/s)
Wing loading: 20.8 lb/ft² (102 kg/m²)
Power/mass: .091 hp/lb (150 W/kg)

Last updated April 09, 2012
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Seawind 300C".
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