Beechcraft Duchess

{{short description|American light twin-engined airplane}} {{Use mdy dates|date=January 2022}} {{Use American English|date=January 2022}}  {{Infobox aircraft |name = Model 76 Duchess |image = File:N60244 1978 Beech 76 Duchess.jpg |caption = A Beech 76 Duchess on final approach |type = Four-seat cabin monoplane |manufacturer = Beechcraft |first_flight = September 1974<ref name="Green">Green, William: ''Observers Aircraft'', page 48. Frederick Warne Publishing, 1980. {{ISBN|0-7232-1604-5}}</ref> |introduction = 1978<ref name="Green"/> |retired = |status = |primary_user = Flight schools<ref name="Green"/> |more_users = |produced = 1978-1983 |number_built = 437 |developed_from = Beechcraft Sierra |variants = }} thumb|US registered 1979 model Duchess thumb|1979 model Duchess

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.<ref name="Green"/><ref name="flying">{{cite web |last1=Collins |first1=Richard L. |title=What Happened to the Piston Twin? |url=https://www.flyingmag.com/what-happened-piston-twin |website=Flying |date=February 5, 2008 |publisher=Bonnier Corporation |accessdate=25 December 2018 |archiveurl=https://web.archive.org/web/20171007032608/https://www.flyingmag.com/what-happened-piston-twin |archivedate=7 October 2017}}</ref>

==Development== Developed as '''Model PD289''' (Preliminary Design 289), the prototype was unveiled on November 4, 1974, although it had first flown in September 1974.<ref name="Green"/><ref name="fiftieth">{{cite book |last1=McDaniel |first1=William H. |title=The History of Beech: Fifty Years of Excellence |date=1982 |publisher=McCormick-Armstrong Co. |location=Wichita, Kansas |isbn=0-911978-00-3}}</ref>{{rp|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.<ref name="Green"/><ref name="kingairmag">{{cite journal |last1=Phillips |first1=Edward |title=The "Baby Beechcraft" - Part Two |journal=KingAir Magazine |date=8 June 2017 |url=http://www.kingairmagazine.com/article/2465/}}</ref>

The first production version flew on 24 May 1977, and the name "Duchess" was chosen through a company competition.<ref name="Green"/><ref name="fiftieth" /> Construction of the Duchess was set for a new factory built at the Liberal Division,<ref name="AWST">{{cite journal |title=To provide increased final assembly facilities |journal=Aviation Week & Space Technology |date=20 December 1976 |page=15}}</ref> with deliveries beginning early in 1978.<ref name="fiftieth" />{{rp|473}}

Production of the Duchess continued until 1983, with no significant changes.<ref>{{cite journal |title=Beech Plans to Close Plant at Liberal, Kan. |journal=Aviation Week & Space Technology |date=18 February 1985 |page=27}}</ref> A single example was tested with turbocharged engines in 1979, but did not proceed to production.<ref name="perfection" />{{rp|56}}

==Design== The Duchess is an all-metal low-wing monoplane with retractable tricycle landing gear and a T-tail. It seats four.<ref>{{cite book |last= Frawley|first= Gerard|title=The International Directory of Civil Aircraft, 2003-2004 |year=2003 |publisher=Aerospace Publications Pty Ltd |location= Fyshwick, ACT, Australia |isbn=1-875671-58-7 |page=41 }}</ref> The design used components and the bonded wing construction from Beechcraft's single-engined Musketeer line.<ref name="perfection">{{cite book |last1=Phillips |first1=Edward H. |title=Beechcraft: Pursuit of Perfection |date=1992 |publisher=Flying Books |location=Eagan, Minnesota |isbn=0-911139-11-7 |edition=2nd}}</ref>{{rp|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.<ref name=avweb>{{cite web|url=https://www.avweb.com/features/beechcraft-duchess/ |title=Beechcraft Duchess |website=avweb.com |author= |date=5 August 2005 |access-date=26 July 2021}}</ref> Nose landing gear from the A36 Bonanza was used.<ref name=avweb/>

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.<ref name="Plane and Pilot">Plane and Pilot: ''1978 Aircraft Directory'', page 84. Werner & Werner Corp, Santa Monica CA, 1977. {{ISBN|0-918312-00-0}}</ref>

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.<ref name="perfection" />{{rp|56}}

The Duchess wing is of aluminum honeycomb construction fastened by bonding, rather than rivets, to reduce cost and produce a smoother aerodynamic surface.<ref name="Plane and Pilot"/>

===T-tail=== 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.",<ref name="Plane and Pilot"/> while Gerald Foster said: "[Beechcraft's] interest in T-tails was perhaps an affectation triggered by their wide use on jet airliners".<ref name="Foster">Montgomery, MR & Gerald Foster: ''A Field Guide to Airplanes, Second Edition'', page 92. Houghton Mifflin Company, 1992. {{ISBN|0-395-62888-1}}</ref> ''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 {{convert|15|lb|kg}} of weight.<ref name=avweb/> Additionally, the T-tail design moved the stabilizer rearward, increasing its effectiveness and giving the aircraft a broader center of gravity range.<ref name=avweb/> The later Piper Seminole also adopted a T-tail.<ref name=avweb/>

==Variants== ;Model 76 Duchess :Four-seat, twin-engine (Lycoming O-360), low-winged trainer with bonded aluminum construction. ;Model 76TC Duchess :Unofficial designation for single test aircraft using turbocharged Lycoming O-360.

==Operators== The aircraft remains popular with flight training schools.

* Beechcraft - Tested one Duchess to investigate its spin recovery characteristics in conjunction with NASA.<ref>{{cite book |last1=Stowell |first1=Rick |title=The Light Airplane Pilot's Guide to Stall/spin Awareness: Featuring the PARE Spin Recovery Checklsit |date=2007 |publisher=Rich Stowell, Master CFI-A |isbn=9781879425439 |page=447}}</ref> *National Test Pilot School - Operates one Duchess.<ref>{{cite web |title=Beech 76A Duchess |url=https://www.ntps.edu/aircraft/beech-76a-duchess.html |website=NTPS |accessdate=25 December 2018}}</ref> *Purdue University - Uses a Duchess modified with air sampling equipment as ''Airborne Laboratory Atmospheric Research (ALAR)''.<ref>{{cite web |title=Army Instrumentation Facility: Airborne Laboratory Atmospheric Research (ALAR) |url=http://jafci.chem.purdue.edu/projects/alar.html |website=Purdue University |accessdate=25 December 2018 |archiveurl=https://web.archive.org/web/20180324183013/http://jafci.chem.purdue.edu/projects/alar.html |archivedate=24 March 2018}}</ref> *Scaled Composites - Uses one Duchess as a test aircraft.<ref>{{cite web |title=Rutan Voyager |url=https://airandspace.si.edu/collection-objects/rutan-voyager |website=Smithsonian: National Air and Space Museum |accessdate=25 December 2018 |archive-date=July 20, 2018 |archive-url=https://web.archive.org/web/20180720215600/https://airandspace.si.edu/collection-objects/rutan-voyager |url-status=dead }}</ref><ref>{{cite web |title=Scaled Composites: SpaceShipOne |url=https://spaceflight.nasa.gov/outreach/SignificantIncidents/assets/combined-white-knight---spaceshipone-flight-tests.pdf |archive-url=https://web.archive.org/web/20161229201841/http://spaceflight.nasa.gov/outreach/SignificantIncidents/assets/combined-white-knight---spaceshipone-flight-tests.pdf |url-status=dead |archive-date=29 December 2016 |website=National Aeronautics and Space Administration |accessdate=25 December 2018 |page=3}}</ref>

==Specifications== frameless|right|3-view line drawing of the Beechcraft 76 Duchess thumb|1976 model Duchess instrument panel {{Aircraft specs |ref=''Jane's All The World's Aircraft 1980–81.''<ref name="JAWA80 p268-9">Taylor 1980, pp. 268–269.</ref> |prime units?=kts  |genhide=

|crew=1 |capacity=3 passengers |length sigfig=3 |length m= |length ft=29 |length in=0+1/2 |span m= |span ft=38 |span in=0 |height m= |height ft=9 |height in=6 |wing area sqm= |wing area sqft=181 |airfoil=NACA 63<sub>2</sub>A415 |aspect ratio=7.973:1 |empty weight kg= |empty weight lb=2460 |gross weight kg= |max takeoff weight lb=3900 |fuel capacity={{convert|100|USgal|impgal L|abbr=on}}  |eng1 number=2 |eng1 name= Lycoming O-360-A1G6D |eng1 type=air-cooled flat-four engines |eng1 kw= |eng1 hp=180

|prop blade number=2 |prop name=Hartzell HC-M2YR-2C(L)EUF/F(J)C 7666A constant speed propellers |prop dia m= |prop dia ft= |prop dia in=

|perfhide=

|max speed kmh= |max speed mph= |max speed kts= |max speed mach= |never exceed speed kts=171 |cruise speed kmh= |cruise speed mph= |cruise speed kts=158 |cruise speed note=at {{convert|10000|ft|m|abbr=on}} |stall speed kts=60 |stall speed note=power off, flaps down, IAS |range km= |range miles= |range nmi=780 |range note=at {{convert|12000|ft|m|abbr=on}}, econ cruise |ceiling m= |ceiling ft=19650 |climb rate ms= |climb rate ftmin=1248 |more performance=

|avionics= }}

==See also== {{aircontent |related= * Beechcraft Musketeer |similar aircraft= * Cessna 310 * Gulfstream American GA-7 Cougar * Piper Seminole |see also= }}

==References== {{Reflist}}

* {{cite book|last=Taylor|first=John W. R.|title=Jane's All The World's Aircraft 1980–81|year=1980|publisher=Jane's Publishing Company|location=London|isbn=0-7106-0705-9|authorlink=John W. R. Taylor}}

==External links== {{commons category|Beechcraft Duchess}}

Duchess Category:1970s United States civil trainer aircraft Category:Low-wing aircraft Category:T-tail aircraft Category:Aircraft first flown in 1974 Category:Twin piston-engined tractor aircraft Category:Aircraft with retractable tricycle landing gear