Thursday, April 1, 2004
The New Super Decathlon
American Champion 8KCAB offers some of the best aerobatic talent in the two-seat, sportplane class
Rich, I know you can’t see the ball from the back seat, but if you could, you’d be rolling with laughter,” I said. I was flying Rich Manor’s new Super Decathlon in left-echelon formation 20 feet from our old friend Saratoga SP photo ship, and my lazy feet were out of practice at flying an airplane with considerable adverse yaw. The ball bounced back and forth out of its cage as I maneuvered on the Saratoga, the slip indicator only occasionally stopping in the center. It had been several years since I’d flown a Super Decathlon, and my rusty technique showed. Gotta unlearn those bad habits, I thought. Too many hours in Mooneys/Bonanzas/Malibus/Centurions and other modern designs that forgive poor rudder coordination.
The good news was that the new American Champion 8KCAB was an absolute joy to hold in place for Jim Lawrence’s camera. The fast ailerons and sensitive elevator provided quick response for maneuvering on the photo ship, balanced by a high drag profile that allowed me to drive the airplane into position with power and stop it exactly where I wanted it by simply easing back on the throttle (an interesting contrast to the previous day’s air-to-air session in a Citation CJ-2, a slightly cleaner design). I even tried some rolls, loops and hammerheads for Lawrence’s lens, and the responsive taildragger was forgiving and obviously more proficient than I was.
In fact, the Super Decathlon has always represented one of the best combinations of utility, comfort and aerobatic talent in the two-seat, sportplane class. Since its introduction in 1977 as a powered-up version of the original Decathlon, the 180 hp Super Decathlon has represented perhaps the best compromise between a utiliplane and a pure acro trainer.
Super Decathlons were originally Bellancas, produced between 1977 and 1980. American Champion purchased the type certificate in the early 1990s and began delivering Supers in 1992, followed closely by Scouts and Citabrias, the latter under the name Explorer. The new company reasoned the original airplane was a well-thought-out design and elected to leave the basic machine alone. As a result, the 2003 Super Decathlon remains essentially the box it came in back in the late ‘70s.
That’s not to suggest there have been no changes, just none that are visible. In addition to increasing horsepower on the 150 hp models (to 160 hp), American Champion initiated installation of all-metal wings, though the airplane remains fabric-covered. Older Super Decathlons utilized Sitka Spruce spars with aluminum ribs. The debate regarding wood versus metal has been raging for at least 70 years and will probably endure for another 70, and there are still plenty of champions for wood construction. Some pilots argue that wood is a more logical material for aerobatic airplanes than metal because wood has no memory. Stress it short of breaking, and it will return to its original shape. Metal is inherently stronger, but flex it enough times, and it will eventually fail. Aluminum advocates argue wood will break at a lower G loading. There are no longer any wood wing acro airplanes produced in the U.S., if that tells you anything.
Aerodynamically, the Super Decathlon is a fairly simple machine. In contrast to the derivative Citabria, the Super Decathlon’s airfoil is a semi-symmetrical, NACA 1412 section with beefier spars and additional trusses to withstand loads of +6 and -5 G’s. Though the wing is unfettered by flaps, it does sport aileron shovels. Shovels, sometimes called spades, are a kind of poor man’s power steering that help lighten roll forces by deflecting down on the up aileron and vice versa on the opposite side to gather more relative airflow.
Page 1 of 4
Labels: Piston Singles