| Model 76 Duchess | |
|---|---|
| |
| A Beech 76 Duchess on final approach | |
| Role | Four-seat cabin monoplane |
| Manufacturer | Beechcraft |
| First flight | September 1974[1] |
| Introduction | 1978[1] |
| Primary user | Flight schools[1] |
| Produced | 1978-1983 |
| Number built | 437 |
| Developed from | Beechcraft Sierra |
The Beechcraft Model 76 Duchess is an American twin-engined monoplane built by Beechcraft intended partly as a low cost introduction to twin-engine aircraft.[1][2]
Developed as Model PD289 (Preliminary Design 289), the prototype was unveiled on November 4, 1974, although it had first flown in September 1974.[1][3]: 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.[1][4]
The first production version flew on 24 May 1977, and the name "Duchess" was chosen through a company competition.[1][3] Construction of the Duchess was set for a new factory built at the Liberal Division,[5] with deliveries beginning early in 1978.[3]: 473
Production of the Duchess continued until 1983, with no significant changes.[6] A single example was tested with turbocharged engines in 1979, but did not proceed to production.[7]: 56
The Duchess is an all-metal low-wing monoplane with retractable tricycle landing gear and a T-tail. It seats four.[8] The design used components and the bonded wing construction from Beechcraft's single-engined Musketeer line.[7]: 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.[9] Nose landing gear from the A36 Bonanza was used.[9]
The Model 76 incorporates right and left "handed" Lycoming O-360 engines that rotate in opposing directions to eliminate the critical engine during single engine operation.[10]
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.[7]: 56
The Duchess wing is of aluminum honeycomb construction fastened by bonding, rather than rivets, to reduce cost and produce a smoother aerodynamic surface.[10]
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.",[10] while Gerald Foster said: "[Beechcraft's] interest in T-tails was perhaps an affectation triggered by their wide use on jet airliners".[11] AVweb wrote 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.[9] Additionally, the T-tail design moved the stabilizer rearward, increasing its effectiveness and giving the aircraft a broader center of gravity range.[9] The later Piper Seminole also adopted a T-tail.[9]
The aircraft remains popular with flight training schools.
Data from Jane's All The World's Aircraft 1980–81.[17]
General characteristics
Performance
