Single Seat Scorpion One Kit Helicopter
Powered by a 115-hp engine, this whirlybird cruises at 75 mph and has a 140-mile range. You can build it from 15 separate kits for a total outlay of about $3650
ARTICLE DATE: March 1972
THE SCORPION is a rare bird — a homebuilt that is a true helicopter, not an autogyro. The difference? A copter’s rotor is powered while that of an autogyro spins only in reaction to aerodynamic forces.
It’s a more sophisticated — and more expensive — form of air transportation than its simpler rotary-wing cousin. The Scorpion comes in kit form — in 15 different kits, to be exact.
There’s one for every major component—the rotor head, the powerplant, landing gear, and so on. The advantage to the homebuilder is that he can buy a few kits at a time, building the bird piecemeal and laying out hundreds—instead of thousands — of dollars at a clip. The Scorpion is not cheap. Total price, less engine, comes to about $3650.
The Scorpion is a souped-up version of a copter first flown by B. J. Schramm, its designer, in 1965. Powerplants are outboard marine engines: an 85-hp Johnson, or a 100-hp or 115-hp Evinrude. The four-cylinder Evinrudes have proven popular because of the extra power.
LEFT: Cockpit is small but uncluttered and comfortable.
RIGHT: FROM LANDING SKID to rotor, the Scorpion stands six feet high. A two-seat model is also available.
A 115-hp Scorpion helicopter has an empty weight of 450 pounds and a gross weight of 750 pounds. It boasts a maximum speed of 85 mph and a cruise speed of 75. Rate of climb is 1200 feet per minute and the service ceiling is said to be 12,000 feet. Normal fuel capacity of 10 gallons provides for a top range of about 140 miles.
The airframe is a simple tubular steel job with a variety of fiberglass pilot enclosures available. The main rotor is 20 feet in diameter and the tail rotor 3 feet 4 inches. Overall length is 17 feet and the height hits 6 feet.
LEFT: RESEMBLING A BIG FLYING BUG, “stripped” version of Scorpion moves slowly across a California field.
RIGHT: FIBERGLASS FUSELAGE, bubble windshield, wheeled landing gear can easily be added to basic craft.
The rotor system incorporate s a two – bladed, semirigid main rotor and a Schramm-developed Tractable Control Rotor System. The rotor hub is fabricated of aluminum and the blades are attached to it by retention straps. The two-bladed tail rotor is also aluminum.
Though the Scorpion helicopter could never be considered the typical homebuilt craft, it has proved popular among the do-it-your-self set. Last year, a dozen Scorpions showed up at a Midwest airshow.
LOOPED CABLE RUNS THROUGH ROTOR SHAFT (photo at left) to provide pitch control. V-belts (center) transmit power from the engine to the small tail rotor. Favorite powerplant among home-built helicopter flyers is four-cylinder, 115-hp Evinrude marine engine. It provides more muscle for faster climbs and hotter performance.
EDITOR: Add a modern Inntec 800cc engine from an Atrtic Cat, round out the windscreen to the nose, and you are “still” looking at a very capable “and” affordable single seat helicopter.
what does it cost for all the plans to build the scorpion 133 ( two seat ) helicopter using different parts ?
To many variables – it depends! Expect to be spending at least $10k plus though, including rotorblades and engine.