Mitchell U-2 Superwing

摘要

TWO HUNDRED FIFTY HOURS, according to Scottish-American designer Don Mitchell, was the amount of time required for an airplane hobbyist of average skill to assemble the airframe of his ultralight U-2 Superwing-plus another hundred hours to install the engine and paint it. A refinement of the B-10 design Mitchell had first flown in 1976, this 1979 model improved upon the earlier airplane by adding a fully enclosed cockpit and wingtip rudders that could be operated independently for yaw control or simultaneously for aerodynamic braking. (The pitch and roll control came courtesy of stabilators on the trailing edge of each outboard wing panel.) Featuring nose-wheel steering and braking, the U-2 could use retractable or fixed landing gear, according to each builder's preference. But what was likely even more attractive to the approximately 1,500 buyers who'd purchased U-2 kits at a base sticker price of $2,795 by the mid-1980s was the ultralight's ability to fly under the power of a small, two-cycle pusher engine or as a sailplane when they shut the engine down. With a 34-foot wingspan and an empty weight of only 335 pounds, the Superwing had an advertised lift-to-drag ratio of 25∶1. It wasn't much fun to fly in high winds, pilots reported, but in every other respect, the Superwing maximized efficiency...and delight.