Beech Aircraft Corporation’s versatile Model 300 and Model B300 exemplified the company’s determination to keep a firm grip on the premier cabin-class, turboprop market segment
As the decade of the 1970s came to a close, management at Beech Aircraft Corporation decided the time had come to expand the company’s King Air product line. Although sales of the Model 200 Super King Air and its successor, the Model B200 that entered service in 1981, remained strong, the advent of Special Federal Aviation Regulation 41C (SFAR 41C) provided a window of opportunity for the airframe manufacturer to offer customers a more capable Super King Air.
Under provisions of SFAR 41C, the maximum takeoff weight (MTOW) could be increased beyond the limit of 12,500 pounds as prescribed by FAR Part 23, under which the Model 200 was originally certified in December 1973. Although temporary in nature, the new rule allowed small, propeller-driven airplanes to seek a MTOW of up to 14,000 pounds – a definite advantage that the company could not afford to ignore. The rule, however, also mandated additional airworthiness requirements to warrant the higher MTOW.
As a result, Beech Aircraft engineers began a systems and performance upgrade program for the Model 200 that would transform it into the improved Model 300. In addition to the higher takeoff weight, the latest version of the Super King Air would incorporate a number of significant upgrades. Chief among these were installation of more powerful Pratt & Whitney Canada PT6A-60 turboprop engines each rated at 1,050 shaft horsepower (shp), new exhaust stacks and four-blade propellers.
The powerplants were enclosed in “pitot-type” cowlings that offered improved air intake efficiency at high altitudes compared with the previous cowling design. Other modifications to the basic Model 200 airframe included relocating the wing leading edge forward 5 inches and installing a 3,000-psi hydraulic landing gear system (replacing the electro-mechanical system used in the Model 200 series up until serial number BB-1193), and a multi-bus electrical architecture.
These and other systems modifications were made to Model 200 serial number BB-343 that also had served as the prototype Model B200. With company senior engineering test pilot Bud Francis in the left seat and fellow test pilot George Bromley flying as co-pilot, the reengineered Super King Air first flew October 6, 1981. Nearly two years later on September 3, 1983, the pre-production prototype Model 300 took off from Beech Field under the command of company test pilot Vaughn Gregg.
In January 1984, Federal Aviation Administration (FAA) certification was granted to the Model 300 under an amendment to the Model 200’s original Approved Type Certificate designated A24CE. Initial deliveries to customers began early that year. A total of 27 airplanes left the factory in 1984 followed by 60 in 1985 – the highest year of production for the company’s new flagship Super King Air. Another batch was delivered in 1986 and 104 Model 300s rolled off the production line from 1987-1991. In addition, in 1987-1988 the company built 19 Model 300s to serve the FAA as national airway/navigation systems inspection and certification aircraft. These special King Airs were issued the distinct serial numbers FF-1 through FF-19.
The temporary nature of SFAR 41C essentially limited the number of Model 300s that could be built. When the regulation expired, it automatically terminated the airplane’s production certificate, which occurred October 17, 1991. Facing a limited market in the United States for the “heavyweight” version of the Model 300, Beech Aircraft turned its attention to offering the airplane as a “lightweight” version (MTOW 12,500 pounds) of the Super King Air to customers in Europe and other regions of the world.
With future expiration of SFAR 41C firmly established by the FAA, in 1988 Beech Aircraft announced its intention to develop the Model 300LW, although the standard Model 300 would continue to be available in the United States but only at a MTOW of 12,500 pounds, as permitted by FAR Part 23 rules. As for the Model 300LW, it received special certification under European airworthiness regulations at a MTOW of 12,500 pounds (the lower takeoff weight also reduced airway user fees that would have been higher if the 14,000-pound limit was approved). According to Beechcraft Corporation, from 1984-1994, a total of 230 Model 300 and 300LW were built. The 300LW Super King Air, however, were selected units built within the production run of the Model 300, and their data does not break out which ones were straight 300s and which were 300LWs. In addition, Beech Aircraft offered customers a kit that included an airspeed indicator with appropriate markings as well as specific pages that were inserted into the FAA-approved Airplane Flight Manual. The kit gave customers the ability to convert a Model 300 into a Model 300LW or reconvert to a Model 300.
In terms of performance, the Model 300 had a maximum speed (in level flight) of 317 knots (365 mph) and a maximum cruising speed of 315 knots (363 mph). Maximum rate of climb (sea level) was an impressive 3,277 feet per minute (fpm), decreasing to 867 fpm (sea level) with one engine inoperative. Empty weight increased to 8,580 pounds compared with 8,060 pounds for the B200; zero fuel weight increased to 11,500 pounds from 11,000 pounds (B200). Best range of 2,273 statute miles was achieved at an altitude of 35,000 feet, decreasing to 1,215 miles at an altitude of 18,000 feet.
Always focused on the future, Beech Aircraft Corporation officials knew the Model 300’s days were numbered, and as early as 1988, design of its successor was well underway. It would prove to be an airplane that lived up to its famous name – Super King Air – by being a “super-capable” hauler of both people and cargo. Dubbed the Model B300 Super King Air, the latest company flagship was introduced at the 1989 National Business Aircraft Association convention and would be marketed under the designation Super King Air Model 350 (in 1996 the word “Super” was deleted from the designation of the B200, B300 and Model 350, which were rebadged as the King Air).
The most salient alteration made to the Model B300 airframe centered on a 34-inch extension of the fuselage. The “stretch” was achieved by adding 14.4 inches forward and 19.6 inches aft of the main spar, respectively, according to Bob Pedroja, former project engineer for the Model 350. The three-foot extension increased the length of the passenger cabin to 19 feet, 6 inches and permitted the installation of two more windows on each side of the cabin, bringing the total per side to seven. In addition, overall wingspan was increased by 18 inches to 57 feet, 11 inches, and winglets were added to the wing tips.
The B300 retained the Pratt & Whitney Canada PT6A-60A turboprop engines of its predecessor, each still rated at 1,050 shp. From an operator’s viewpoint, however, the Model 350’s ability to take off (sea level, ISA conditions) with a full payload and fuel tanks full (539 gallons) was the most important improvement of all. First flight of the B300 pre-production prototype (serial number FA-1) occurred Sept. 13, 1988, under the command of Bud Francis. FAA certification was achieved December 12, 1989, under provisions of FAR Part 23 through Amendment 34 as applied to the Commuter Aircraft Category.
By taking advantage of the Commuter Aircraft rules, Beech Aircraft was able to boost the B300’s MTOW (and maximum landing weight) to 15,000 pounds – a 1,000-pound increase compared with the B300 Super King Air. Empty weight rose to 9,051 pounds and zero fuel weight was increased to 12,500 pounds. The maximum speed was 315 knots (363 mph), and service ceiling exceeded 35,000 feet. Initial deliveries of the Super King Air 350 began in March 1990. The company also offered the Model B300C version that was equipped with a combined airstair/cargo door (measuring 52 inches by 52 inches) on the left side of the aft fuselage section. FAA certification of the cargo door version occurred in 1990. The Super King Air 350 quickly proved itself in the highly competitive cabin-class, turboprop market segment.