applications The Cessna 310 was a common charter aircraft for the many air taxi firms that sprang up in the general aviation boom that followed World War II. The advantages of the Cessna 310 over its contemporaries, such as the Piper PA-23, were its speed, operating costs and aftermarket modifications, such as the Robertson STOL kits that made it popular worldwide for its bush flying characteristics. It could use short runways, while at the same time carrying a large useful load of . or more, at speeds that were high for a twin engine piston aircraft. Military applications In 1957, the United States Air Force (USAF) selected the Cessna 310 for service as a light utility aircraft for transport and administrative support. The USAF purchased 160 unmodified 310A aircraft with the designation L-27A and unofficially nicknamed Blue Canoe, later changed to U-3A in 1962. An additional 36 upgraded 310 designated L-27B (later U-3B) were delivered in 1960–61; these aircraft were essentially military 310Fs and as such equipped with the more powerful engines and can be identified by their extra cabin windows, longer nose and swept vertical fin. A USAF study after one year of operational service found the U-3A had direct operating costs of less than $12 an hour. The U-3 saw active service in a support role when the USAF deployed aircraft to South Vietnam during the Vietnam War, where they were used on courier flights between air bases. Some USAF aircraft were later transferred to the U.S. Army and U.S. Navy and the type continued in United States military service into the mid-1970s. Notable private flights On December 19, 1992, Cuban defector Major Orestes Lorenzo Pérez returned to Cuba in a 1961 Cessna 310 to retrieve his wife and two sons. Flying without lights, at low speed and very low altitude to avoid Cuban radar, Pérez picked up his family by landing on the coastal highway of Varadero beach, Matanzas Province, east of Havana and managed a successful safe return to Marathon, Florida. Variants 310 Initial production variant, powered by two Continental O-470-B or O-470-M engines with carburetors, with maximum takeoff weight of ; in production for 1955-1957 model years, 547 built. 310A Military version of the 310 for the United States Air Force, designated L-27A and later U-3A; with Continental O-470-M engines and maximum takeoff weight of ; 161 built. 310B Model produced in 1958, with new