Around 500 of these aircraft were manufactured in Pittsburg, Kansas from 1954 until 1974 by the Helio Aircraft Company. The design featured four leading edge slats that deployed automatically, and large trailing edge flaps. The engine was the 295 hp Lycoming GO-480, which had a gearbox that lowered the output RPM and allowed for the use of a large three-bladed propeller to further improve takeoff performance. Couriers were famous for their takeoffs, which often took only a few plane lengths and then climbed at very high angles. The engine, however, required constant maintenance and was a major downside to the design. During the early 1980s, new owners (Helio Aircraft Ltd.) made an attempt to build new aircraft with direct-drive Lycoming engines, to replace troublesome and expensive geared engines. In a further effort to reduce weight, a new composite landing gear was featured. The new models also featured modest winglets. Two models were produced, the H-800 and H-700. A total of 18 aircraft were built. The rights to the Helio Stallion and Helio Courier were acquired by Helio Aircraft of Prescott, Arizona, and was to be returned to production. For more information on the design, development and 25 variants, click here. Specifications below are for the U-10D Super Courier. Trigear Courier Stallion Twin Courier