|Model 76 Duchess|
|1978 model Beech 76 Duchess operated by the National Test Pilot School at the Mojave Airport|
|Role||Four-seat cabin monoplane|
|First flight||September 1974|
|Primary user||Flight schools|
|Developed from||Beechcraft Sierra|
Developed as Model PD289 (Preliminary Design 289), the prototype was unveiled on November 4, 1974, although it had first flown in September 1974.: 409–410 The Model 76 was designed as an economical twin-engine trainer for the Beech Aero Centers and to compete with the similar Gulfstream Cougar as well as the Cessna 310.
The first production version flew on 24 May 1977, and the name "Duchess" was chosen through a company competition. Construction of the Duchess was set for a new factory built at the Liberal Division, with deliveries beginning early in 1978.: 473
The Duchess is an all-metal low-wing monoplane with retractable tricycle landing gear and a T-tail. It seats four. The design used components and the bonded wing construction from Beechcraft's single-engined Musketeer line.: 55 The basic fuselage and wing structure was adapted from the Model 24 Sierra, a Musketeer variant with retractable landing gear, but the Sierra wing spar was redesigned to support the added weight of the engines. Nose landing gear from the A36 Bonanza was used.
In 1979, a single example was converted to test the turbocharged versions of the engine. The cowlings were reshaped and the exhaust moved to accommodate the aft-mounted turbochargers.: 56
The Duchess wing is of aluminum honeycomb construction fastened by bonding, rather than rivets, to reduce cost and produce a smoother aerodynamic surface.
The use of a T-tail on the Model 76 met with mixed critical reception when the aircraft was introduced. Plane & Pilot pronounced: "Outstanding design characteristics of the new Duchess include an aerodynamically advantageous T-tail, which places the horizontal surfaces above the propeller slipstream for better stability and handling.", while Gerald Foster said: "[Beechcraft's] interest in T-tails was perhaps an affectation triggered by their wide use on jet airliners". AVweb claims that Beechcraft adopted the T-tail after flight tests revealed that the initially used conventional horizontal stabilizer was too small and suffered from buffeting problems, increasing noise and vibration during flight; moving the horizontal stabilizer out of the propeller slipstream eliminated the buffeting and the need for enlargement while adding only 15 pounds (6.8 kg) of weight. Additionally, the T-tail design moved the stabilizer rearward, increasing its effectiveness and giving the aircraft a broader center of gravity range. The later Piper Seminole also adopted a T-tail.
The aircraft remains popular with flight training schools.
Data from Jane's All The World's Aircraft 1980–81.
Aircraft of comparable role, configuration, and era
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