Speed: 55 mph
Cruise altitude: 10-12 inches
Max. altitude: 24 inches
Payload: 325 lbs
Fuel capacity: 1 gallon
Range: 25 miles
Weight: 325 lbs
Propellers: Two x 36 inch x 24 pitch
Engine: 35 hp Briggs & Stratton
Climb gradient: 30%
Length: 19 feet
Width: 96 inches
Height: 90 inches with tail
Advancing the throttle above 2,000 RPM with bring the craft up on cushion and begin a slow acceleration. This rpm is used to depart the landing zone. Advancing the throttle to full (3,600 rpm) will rapidly accelerate the craft. On a calm day the craft will achieve 50+ mph in just 6 seconds or 350 feet. After the craft is airborne it flies similarly to a small airplane. Moving the joystick left causes a slight bank and shallow turn. Because the craft is not fitted with ailerons it skids thru the turns much like a hovercraft. At cruise speed (45 to 50 mph) the craft rides very smooth. You can pass over waves without feeling any effect.
Nearly 25 scale models were constructed before the first tandem wing craft assembly began. This is the way we test most of our craft. It is much easier to make corrections in a styrofoam model than in a full size prototype. We tested wing angles, surface areas, 2,3 and 4 wing models, propeller angle, single propeller and dual propeller, weight and balance issues, control combinations and many different wing tip styles.
Most people are surprised to see this craft drive from the water to the land much like a typical hovercraft. This was a very important consideration while developing the craft. It had to be self launching (land to water) and able to transition under its own power from the water back up onto the land. This is made easy by the positioning of the propellers. They are slanted back at a 20 degree angle to help air flow directly under with wings. With only a slight advancement of the throttle this craft comes up on cushion.
The craft is half ''old school'' and half ''new school''. The body is made from a wood rib and stringer combination with most of the strength coming from the skins. Wings are made of a sandwich foam/fiberglass construction. The bottom trailing edges of the wings are laminated with 1/8 inch plywood to prevent excessive wear from waves slapping the surface.
Controls: Version 1:
The first variation of this craft had a completely different control system than the controls we are using now. Initially the engine was directly mounted to a 36 inch propeller. The engine was mounted on a swivel bearing system that allowed the engine to rotate left and right. Turning the engine left would thrust the nose of the craft left resulting in a turn or bank. This system worked very well at low speed and high speed. Two issues were the high load required to turn the engine left (torque related) and the close proximity of the propeller to the water. Occasionally the propeller would chop water while decelerating.
You will notice the huge vertical stabilizer in the rear of the craft. This stabilizer control grew in size throughout the testing phase as we were trying to increase low speed maneuverability. Another reason for its large size is that the propellers being so far forward induced negative stability. This had to be compensated for by adding surface area to the stabilizer. This surface is controlled with the left and right movement of the joystick.
The elevator is controlled by moving the joystick backward and forward. This motion controls the trailing edge of the rear wing. A very small input gives precise control over the attitude of the craft.
Each propeller is able to be disengaged through foot activated belt tensioning system. These controls are set up like rudder peddles on an airplane. Pressing left would lessen the tension on the left propeller allowing the belt to slip. The right propeller would then yaw the craft in the direction of the depressed peddle.
Throttle control is a motorcycle style twist grip on the top of the joystick.
These types of craft have been under development by Universal Hovercraft for nearly 15 years now. In the future we plan to increase the horsepower of our current prototype from 35 to 45. We may also reconfigure the drive system to include a rear mounted thrust propeller. Further into the future we plan to build larger versions of the Tandem Wing capable of flying 4 passengers over rough water.
Plans are currently not available for this craft. We may offer plans in the future although we have not set a date for release. It is our goal to further develop this craft into a better performing, easy to control and safe ground effect vehicle. Periodically we will update this section of the web site with new tandem wing information.
Universal Hovercrafts research and development budget is directly dependant on sales being made to our customers. No outside funding such as government grants or loans have been used to develop these projects. We greatly appreciate our loyal customer base, new customers and future customers. Without you none of this is possible. Thank you for choosing Universal Hovercraft as your hovercraft supplier.