|Cessna 310 / 320|
|1965 Cessna 310J|
|Role||Twin-engined cabin monoplane|
|First flight||January 3, 1953|
|Primary users||General Aviation
United States Air Force
The Cessna 310 is an American six-seat, low-wing, twin-engined monoplane that was produced by Cessna between 1954 and 1980. It was the first twin-engined aircraft that Cessna put into production after World War II.
The 310 first flew on January 3, 1953 with deliveries starting in late 1954. The sleek modern lines of the new twin were backed up by innovative features such as engine exhaust thrust augmenter tubes and the storage of all fuel in tip tanks in early models. In 1964, the engine exhaust was changed to flow under the wing instead of the augmenter tubes, which were considered to be noisy.
Typical of Cessna model naming conventions, a letter was added after the model number to identify changes to the original design over the years. The first significant upgrade to the 310 series was the 310C in 1959, which introduced more powerful 260 hp (194 kW) Continental IO-470-D engines. In 1960 the 310D featured swept back vertical tail surfaces. An extra cabin window was added with the 310F.
The 320 Skyknight was developed from the 310F, which featured turbocharged TSIO-470-B engines and a fourth cabin side-window. The Skyknight was in production between 1961 and 1969 (the 320E was named the Executive Skyknight), when it was replaced by the similar Turbo 310.
The 310G was certified in 1961 and introduced the canted wingtip fuel tanks found on the majority of the Cessna twin-engine product line, marketed as 'stabila-tip' tanks by Cessna because they were meant to aid stability in flight. A single side window replaced the rear two windows on the 310K (certified in late 1965), with optional three-blade propellers being introduced as well. Subsequent developments included the 310Q and turbocharged T310Q with redesigned rear cabin featuring a skylight window, and the final 310R and T310R, identifiable by a lengthened nose containing a baggage compartment. Production ended in 1980.
Over the years there were several modifications to the 310 to improve performance. Noted aircraft engineer Jack Riley produced two variants, The Riley Rocket 310 and the Riley Turbostream 310. Riley replaced the standard Continental 310 hp (230 kW) engines with Lycoming TIO-540 350 hp (261 kW) engines. These turbo-charged intercooled engines were installed with three-blade Hartzell propellers in a counter-rotating configuration to further increase performance and single engine safety. At 5,400 lb (2,400 kg). gross weight the aircraft had a weight to power ratio of 7.71 lb (3.50 kg). per horsepower. This resulted in a cruising speed of 260 knots (480 km/h) at 18,000 feet (5,500 m) and a 3,000fpm rate of climb.
Operational history 
Commercial 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 after market modifications such as the Robertson STOL kits which made it popular world wide for its bush flying characteristics. It could use short runways while at the same time carrying a large useful load of 2,000 lb (910 kg). or more, at high speeds 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 260 hp (194 kW) 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. Some USAF aircraft were later transferred to the US Army and US Navy and the type continued in US military service into the mid 1970s.
- Production aircraft powered by two 240 hp (180 kW) Continental O-470-B engines, 547 built.
- Military version of the 310 for the United States Air Force, designated L-27A and later U-3A, 160 built.
- 310 with new instrument panel, O-470-M engines and minor changes, 225 built.
- 310B with 260 hp (190 kW) IO-470-D engines, increased take-off weight and minor changes, 259 built. Unit cost $59,950 in 1959
- 310C with swept vertical tail and minor detail changes, 268 built.
- Military version of the 310F, designated the L-27B and later U-3B, 36 built.
- 310D with extra cabin window each side, pointed nose, new tip tank shape and other minor changes, 156 built.
- 310F with slimline tip tanks, six-seat cabin, an increased take-off weight and detail changes, 156 built.
- 310G with increased take-off weight and enlarged cabin interior, 148 built.
- 310H with IO-470-U engines, baggage compartments in rear of engine nacelles and minor detail changes, 200 built.
- 310I with minor detailed changes, 200 built.
- 310J with long 'vista view' side windows, increased take-off weight and IO-470-V engines, 245 built.
- 310K with single-piece windshield, re-designed undercarriage, increased fuel capacity and minor changes, 207 built.
- Revised designation for the 310E.
- 310L with revised instrument panel, optional fuel tanks in engine nacelles, IO-470-V-O engines and minor changes, 198 built.
- 310N with a shorter nose undercarriage leg, ventral fin, and optional turbocharged Continental TSIO-520-B engines, 240 built.
- 310P with take-off weight increased to 5,300 lb (2,400 kg) and detailed changes, from the 401st aircraft fitted with a bulged rear cabin roof with rear view window, 1160 built.
- 310Q with three-bladed propellers, lengthened nose with baggage compartment, 5,500 lb (2,500 kg) take-off weight and 285 hp (213 kW) IO-520-M engines, 1332 built.
- Original designation for the Cessna 320.
- 320 Skyknight
- Enlarged version of the 310F with six seats, larger cabin and two turbocharged engines, 110 built.
- 320A Skyknight
- 320 with stabil-tip fuel tanks and minor changes, 47 built.
- 320B Skyknight
- 320A with nacelle baggage lockers and minor changes, 62 built.
- 320C Skyknight
- 320B with a longer cabin, optional seventh seat and minor changes, 73 built.
- 320D Executive Skyknight
- 320C with reshaped rear windows and 285 hp (213 kW) TSIO-520-B engines, 130 built.
- 320E Executive Skyknight
- 320D with pointed nose, single piece windshield, modified undercarriage, increased take-off weight and minor changes, 110 built.
- 320F Executive Skyknight
- 320E with minor changes, 45 built.
- United States military designation for the 310A, later changed to U-3A.
- United States military designation for the 310E/310M, later changed to U-3B.
- L-27A redesignated in 1963.
- L-27B redesignated in 1963.
- Riley 65
- Cessna 310 to 310G by fitting two 240-260 hp (179–194 kW) Continental O-470D/-470M engines.
- Riley Super 310
- Conversion of Cessna 310/320 by fitting two 310 hp (231 kW) Continental TSIO-520-J/-N engines.
- Riley Rocket
- Conversion of Cessna 310 by fitting two 290 hp (216 kW) Lycoming IO-540-A1A5 engines and more fuel.
The aircraft is popular with air charter companies and small feeder airlines, and is operated by private individuals and companies.
Military operators 
Countries known to have operated the U-3/310 include.
- Cessna 310 and 320 models
- United States Air Force received 196 L-27A and L-27B (later redesignated U-3A and B).
- United States Army received 25 ex-US Air Force L-27As (later U-3As) and at least 13 L-27Bs (later U-3B) from 1960.
Accidents and incidents 
- On October 28, 1959, a Cessna 310 carrying Cuban revolutionary Camilo Cienfuegos disappeared over the Atlantic Ocean on a night flight from Camaguey to Havana. Neither the aircraft nor the body of Cienfuegos were ever found.
- On November 26, 1962, a VASP Saab Scandia 90A-1 registration PP-SRA en route from São Paulo-Congonhas to Rio de Janeiro-Santos Dumont collided in the air over the Municipality of Paraibuna, State of São Paulo with a private Cessna 310 registration PT-BRQ en route from Rio de Janeiro-Santos Dumont to São Paulo-Campo de Marte. Both were flying on the same airway in opposite directions and failed to have visual contact. The two aircraft crashed killing all 23 passengers and crew of the Saab and the four occupants of the Cessna.
- On July 19, 1967, a Boeing 727 operating as Piedmont Airlines Flight 22 collided with a Cessna 310 at Hendersonville, North Carolina, USA, killing all 79 people on board both aircraft and three people on the ground.
- On October 16, 1972, U.S. Congressmen Nick Begich of Alaska, and Hale Boggs of Louisiana, disappeared over Alaska while flying in a Cessna 310 during a campaign trip.
- On 19 December 1992, Cuban defector Major Orestes Lorenzo Pérez returned to Cuba in a 1961 Cessna 310 to retrieve his wife Vicky and his 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, 93 mi (150 km) west of Havana and managed a successful safe return to Marathon, Florida.
- As of February 2010[update], the NTSB has recorded 1712 incidents for Cessna 310s since 12 January 1964.
Specifications (1956 model 310) 
Data from 1956 Observers Book of Aircraft
- Crew: one
- Capacity: four passengers
- Length: 27 ft 0 in (8.23 m)
- Wingspan: 35 ft 0 in (10.67 m)
- Height: 10 ft 6 in (3.20 m)
- Empty weight: 2,850 lb (1,293 kg)
- Gross weight: 4,600 lb (2,087 kg)
- Powerplant: 2 × Continental O-470-B horizontally opposed piston engines, 240 hp (180 kW) each
- Maximum speed: 220 mph (354 km/h; 191 kn)
- Cruise speed: 205 mph (178 kn; 330 km/h)
- Range: 1,000 mi (869 nmi; 1,609 km)
- Service ceiling: 20,000 ft (6,096 m)
- Rate of climb: 1,700 ft/min (8.6 m/s)
Notable appearances in media 
See also 
- Aircraft of comparable role, configuration and era
- Demand Media (2008). "The Cessna 310/320". Retrieved 2008-05-04.
- Type Certificate 3A10, p.11
- Type Certificate 3A10, p.19
- Krivinyi, Nikolaus: World Military Aviation, page 148. Arco Publishing Co., 1977. ISBN 0-668-04348-2
- Phillips, Edward H:Wings of Cessna Model 120 to the Citation III, Flying Books, 1986. ISBN 0-911139-05-2
- Flying Magazine: 61. January 1959.
- Taylor 1966, p. 314.
- Taylor 1982, pp. 453–454.
- Andrade 1982, p. 67
- Andrade 1982, p. 106
- Andrade 1982, p.151
- Andrade 1982, p. 157
- Andrade 1982, p.179
- Andrade 1982, p.180
- Andrade 1982, p.222
- Taylor 1982, p. 347.
- Harding 1990, pp. 85–86.
- Andrade 1982, p. 336
- Andrade 1982, p.339
- Andrade 1982, p. 342
- Thomas, Hugh. 1970,1998. Cuba: The Pursuit of Freedom, pp. 842-3. Da Capo Press, New York. ISBN 0-306-80827-7
- "Accident description PP-SRA and PT-BRQ". Aviation Safety Network. Retrieved 2 June 2011.
- Aviation Safety Network (June 2006). "Accident description". Retrieved 2009-07-25.
- "Hale Boggs — Missing in Alaska". Famous Missing Aircraft. Check-Six. Retrieved 17 February 2012.
- Google News, Top Cuban Pilot Defects to US The Deseret News, 21 March 1991, retrieved 5 January 2012
- New York Times, The New York Times, 21 December 1992, retrieved 14 May 2013
- National Transportation Safety Board (February 2010). "Accident Database & Synopses". Retrieved 2010-02-21.
- Green, William: Observers Book of Aircraft, page 56. Frederick Warne Publishing, 1956.
- FAA Type Certificate Data Sheet Number 3A10
- Andrade, John. Militair 1982. London: Aviation Press Limited, 1982. ISBN 0-907898-01-7
- Harding, Stephen. U.S. Army Aircraft Since 1947. Shrewsbury, UK: Airlife Publishing, 1990. ISBN 1-85310-102-8.
- Taylor, John W. R. Jane's All The World's Aircraft 1966–67. London: Sampson Low, Marston & Company, 1966.
- Taylor, John W. R. Jane's All The World's Aircraft 1982–83. London: Jane's Yearbooks, 1982. ISBN 0-7106-0748-2.
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