increases fuel burn from and lowers the certified ceiling from . The supplemental type certificate was issued on 2006-05-12. Operation The Duke was purchased by corporate and private pilot owners. Most were registered in the United States but examples were exported to many countries including Argentina, Australia, Brazil, Canada, Croatia, Finland, France, Germany, Honduras, Iceland, Serbia, Slovenia, Sweden, Switzerland, South Africa and the United Kingdom. One Duke was flown by the Jamaica Defense Force. Many remain in service in the early twenty-first century. In reviewing the aircraft in 2008, Rick Durden of AVweb stated, Production figures Beechcraft 60 : 125 Beechcraft A60 : 121 Beechcraft B60: 350 Specifications (B60) Operators Military operators Jamaica Defence Force See also Notes Bibliography Donald, David (editor). The Encyclopedia of World Aircraft. Leicesrer, UK:Blitz Editions, 1997. . Simpson, Rod. Airlife's World Aircraft. Airlife Publishing Ltd, Shrewsbury, England, 2001. . Simpson, Rod. The General Aviation Handbook. Midland Publishing, Hinckley, England, 2005. . Taylor, John W.R. Jane's All The World's Aircraft 1976–77. London:Jane's Yearbooks, 1976. . Wheeler, Barry C. "World's Air Forces 1979". Flight International, August 4, 1979. Vol. 116, No. 3672. pp. 333–386. External links Duke 1960s United States civil utility aircraft Low-wing aircraft Aircraft first flown in 1966 Twin piston-engined tractor aircraft