Bede BD-10 - Design and Development

Design and Development

The genesis of the BD-10 came about after the Bede BD-5 project in the 1970s, when the Federal Trade Commission (FTC) entered Jim Bede into a consent decree, forbidding him from accepting down payments for aircraft for a period of ten years. Bede worked on numerous other projects during this period with preliminary design begun by 1983 on a small jet. Within weeks of the agreement expiring in 1989, he announced plans for the BD-10J under the aegis of Bede Jet Corporation, at the Spirit of St. Louis Airport.

The BD-5's failure was due largely to the unavailability of a suitable engine; during the BD-5's history one engine company after another either exited the engine business or went bankrupt. Bede started the new design by selecting a suitable commonly available engine and then designing the aircraft around it. The selected engine was the General Electric J85, widely used in a variety of military aircraft and virtually identical to its civilian counterpart, the General Electric CJ-610, available both in new-build and second-hand markets. Perhaps the best known military applications of the J85 are the twin-engined T-38 Talon and the closely related F-5 Freedom Fighter, with the most familiar civilian application being the early Learjet models. The new BD-10J design bore a strong resemblance to the T-38/F-5, although it was much smaller and used only a single engine. The Williams FJ44 and Pratt & Whitney JT12 were also offered as options.

The resulting design featured a shoulder-mounted cropped-delta wing with just over 21 feet (6.4 m) of span and a leading-edge sweep of about 30 degrees. Cropped-delta elevators were also used, although featuring a much greater 50 degree leading sweep. The large canopy extended a fair distance above the fuselage midline, in relative terms, so twin rudders were used on either side to provide clean airflow. All of the controls were strictly mechanical, using pushrods. In order to deal with the increasing control stiffness with increased speed, the design initially specified two control sticks, a small side-stick with limited leverage for low speeds, and a full-sized one mounted in front of the seat with much more leverage for high speeds.

The aircraft was fairly conventional in construction terms, using aluminum sheeting for the majority of the airframe, and fiberglass for certain parts and fillets. The dry weight was only 1,600 lb (725 kg), about the same as light aircraft like the Cessna 172. Given the engine's nominal 3,000 lbf (13 kN) thrust at sea level, the design was significantly overpowered, generally considered a major advantage for any aircraft. Performance estimates were extremely exciting; after a takeoff roll of only 850 ft (260 m) even at a fully fueled weight of 4,400 lb (2,000 kg), the aircraft would climb at 20,000 ft/min to a cruising altitude of 45,000 ft (14,000 m). At this altitude it would cruise at Mach 0.9 (520 ktas, 595 mph) and at full power would reach Mach 1.4. The high-altitude cruise allowed flights up to 2,000 miles (3,200 km).