Thursday, April 1, 2004
The New Super Decathlon
American Champion 8KCAB offers some of the best aerobatic talent in the two-seat, sportplane class
Inside the airplane, controls couldn’t be much simpler, and systems are mostly non-existent. All electrical switches are mounted on a panel directly above the pilot’s left shoulder where they’re accessible to either seat. Elevator trim is also positioned on the left side panel where both pilots can reach it. Only the starter, mixture and prop controls are dedicated to the front cockpit. A conventional joystick controls pitch and roll, and the rudder pedals are large and effective. The tailwheel is steerable, and an extra stab on either brake pedal will kick the rear wheel into full caster, allowing easy maneuvering in tight spaces.
Power is provided by an AEIO-360-H1B Lycoming, rated for 180 hp at 2,700 rpm, fitted with an inverted fuel and oil system and capable of sustained inverted flight for up to two minutes. Two constant speed props are available on the Super Decathlon, a 74-inch, all-metal Hartzell or a similar diameter, composite MT design. The composite prop is seven pounds lighter, and since Manor has no plans to operate from dirt strips where rocks or debris might chip the blades (not repairable on a composite), he chose the lighter prop.
Any time you fly with a power loading of 10 or less, you can expect good acceleration, and the Super Decathlon doesn’t disappoint when it’s time to take the active. With 169 square feet of wing above and 180 hp out front to lift only 1,800 pounds, the Super leaps off the ground in less than 500 feet and starts uphill as if its tail was on fire. Equally important, the Super Decathlon generates good ascent in the 3,000- to 6,000-foot range where pilots will practice aerobatic maneuvers. This should make the Super a viable trainer at medium-density-altitude airports such as Albuquerque, Denver and Salt Lake City.
Like many two-seaters, the 8KCAB benefits disproportionately from lighter takeoff weights. Book spec for climb at gross is 1,280 fpm, but the airplane will do better at reduced weights with only one soul aboard. In the ‘70s and ‘80s when Super Decathlons were still Bellancas, I ferried a half-dozen of the type from the company’s plant in Osceola, Wis., to California for distributor Ed Carlson and regularly saw climb rates of 1,200 to 1,300 fpm flying solo. Even at the full 1,800-pound gross, the airplanes often manage to reach their factory promise.
Conversely, cruise performance isn’t the trump card of the Super Decathlon, in case anyone cares. Logically, you shouldn’t expect big cross-country numbers with struts, wheels and flying wires hanging in the wind. Manor’s final delivery trip from Wichita to Long Beach, Calif., suggested a reliable cruise speed of 120 knots on about 9.5 gph. With 39 gallons maximum, that limited endurance to three hours plus reserve, worth 350 nm between pit stops.
The Super Decathlon’s designated mission is aerobatics, and that’s how Manor plans to use his airplane. In the real world, Manor sells new and used Cessnas for Tom’s Aircraft in Long Beach, but he keeps the Super Decathlon as a pet and hopes to launch a basic aerobatics course in the near future. The instructor ordered the Super from the factory in early 2003 and configured it specifically for teaching. He deliberately avoided gyros or a vacuum pump because he hoped to fly the airplane primarily for vertical and inverted fun. Similarly, the avionics package consists only of a Garmin GPS/COM and transponder, more than enough but less than too much for VFR operation.
The result is an empty weight of only 1,334 pounds, leaving a useful load of 466 pounds. With two 170-pound pilots in the seats, the airplane will still carry 20 gallons of fuel, more than an hour’s worth of hard acro. Fill the tanks on Manor’s Super, and cabin load is limited to 226 pounds.
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Labels: Piston Singles