Seawind 300C
Encyclopedia
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.
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.
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
.
, powered by a 200 hp Lycoming IO-360 engine. Although top and cruise speeds were respectable, SNA felt that the aircraft needed more power. A 300 hp engine was installed, as well as several modifications, to create the Seawind 3000.
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 has 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.
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."
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
, four-seat, amphibian airplanes that all feature a single tail-mounted engine.
The Seawind line consists of the kit-built
Homebuilt aircraft
Also known as amateur-built aircraft or kit planes, homebuilt aircraft are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch," from plans, or from assembly kits.-Overview:...
Seawind 2000 and Seawind 3000 that were marketed by SNA Inc. of Kimberton, Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, 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
Vertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
. The design is also noted for its long, low profile and sleek curves made practical by composite
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
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
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
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
Avionics
Avionics are electronic systems used on aircraft, artificial satellites and spacecraft.Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles...
.
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
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
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
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
is hinged to the side of hull and folds up into the wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...
for flight and water operations.
An electric/hydraulic powerpack provides hydraulic power for the flaps
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
, landing gear
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
and optional nose-wheel steering. The hydraulic pack and battery
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
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
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...
is slaved to the air rudder for water operation.
Development
The Seawind was originally designed in the early 1980s in Canada. Seawind kitsHomebuilt aircraft
Also known as amateur-built aircraft or kit planes, homebuilt aircraft are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch," from plans, or from assembly kits.-Overview:...
were developed and sold by SNA Inc. of Kimberton, Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, 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
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
Seawind 2000
The Seawind 2000 was the first kit prototypePrototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
, powered by a 200 hp Lycoming IO-360 engine. Although top and cruise speeds were respectable, SNA felt that the aircraft needed more power. A 300 hp 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 hullHull (watercraft)
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...
and step configuration. The Seawind 2000 canopy
Canopy (aircraft)
An aircraft canopy is the transparent enclosure over the cockpit of some types of aircraft. The function of the canopy is to provide a weatherproof and reasonably quiet environment for the aircraft's occupants. The canopy will be as aerodynamically shaped as possible to minimize drag.-History:Very...
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
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
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
Blade pitch
Blade pitch or simply pitch refers to turning the angle of attack of the blades of a propeller or helicopter rotor into or out of the wind to control the production or absorption of power. Wind turbines use this to adjust the rotation speed and the generated power...
to high. However, due to a malfunction, the propeller went into flat (or possibly reverse) pitch
Blade pitch
Blade pitch or simply pitch refers to turning the angle of attack of the blades of a propeller or helicopter rotor into or out of the wind to control the production or absorption of power. Wind turbines use this to adjust the rotation speed and the generated power...
. This caused excessive drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
and prevented the propeller from windmilling. The crew attempted to reach the runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...
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 has felt this was a potential weak point in the Seawind design, although the pylon is capable of 15G
G-force
The g-force associated with an object is its acceleration relative to free-fall. This acceleration experienced by an object is due to the vector sum of non-gravitational forces acting on an object free to move. The accelerations that are not produced by gravity are termed proper accelerations, and...
vertical and 20G
G-force
The g-force associated with an object is its acceleration relative to free-fall. This acceleration experienced by an object is due to the vector sum of non-gravitational forces acting on an object free to move. The accelerations that are not produced by gravity are termed proper accelerations, and...
forward loading, more than twice the certification requirement.
The prototype was rebuilt with a non-reversible constant speed propeller
Constant speed propeller
A constant speed propeller is a type of propeller that can change its blade pitch to take better advantage of the power supplied by an engine in much the same way that a transmission in a car takes better advantage of its power source...
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 523Canadian Aviation Regulations
The Canadian Aviation Regulations are the rules that govern civil aviation in Canada.-Establishment:The CARs became law on October 10, 1996 replacing the former Air Regulations and Air Navigation Orders. The authority for the establishment of the CARs is the Aeronautics Act...
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
Federal Aviation Regulations
The Federal Aviation Regulations, or FARs, are rules prescribed by the Federal Aviation Administration governing all aviation activities in the United States. The FARs are part of Title 14 of the Code of Federal Regulations...
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
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
$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
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
. 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
Stick shaker
A stick shaker is a mechanical device to rapidly and noisily vibrate the control yoke of an aircraft to warn the pilot of an imminent stall...
and stick pusher
Stick pusher
A stick pusher is a device installed in some fixed-wing aircraft to prevent the aircraft from entering an aerodynamic stall. Some large fixed-wing aircraft display poor post-stall handling characteristics or are vulnerable to deep stall...
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
Designated Airworthiness Representative
A Designated Airworthiness Representative is a private person designated by the United States Federal Aviation Administration to act on its behalf in the inspection of amateur-built aircraft and the issuance of airworthiness certificates...
, 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."