Cessna 310

The Cessna 310 is an American four-to-six-seat, low-wing, twin-engine monoplane produced by Cessna between 1954 and 1980. It was the second twin-engine aircraft that Cessna put into production; the first was the Cessna T-50.

Development
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 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 turbocharged 320 Skyknight was developed from the 310F. Equipped with TSIO-470-B engines and featuring an extra cabin window on each side, it 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 a 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 engines with 350 hp Lycoming TIO-540 engines. These turbocharged intercooled engines were installed with three-blade Hartzell propellers in a counter-rotating configuration to further increase performance and single-engine safety. At 5400 lb gross weight the aircraft had a weight to power ratio of 7.71 lb per horsepower. This resulted in a cruising speed of 260 kn at 18000 ft and a 3,000 ft/min rate of climb.

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 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 2000 lb. 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 260 hp 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, 93 mi east of Havana and managed a successful safe return to Marathon, Florida.

Variants



 * 310
 * Initial production variant, powered by two 240 hp Continental O-470-B or O-470-M engines with carburetors, with maximum takeoff weight of 4600 lbs; 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 4830 lbs; 161 built.


 * 310B
 * Model produced in 1958, with new instrument panel, O-470-M engines and maximum takeoff weight of 4700 lbs; 225 built.


 * 310C
 * Model produced in 1959, with 260 hp Continental IO-470-D fuel-injected engines and maximum takeoff weight increased to 4830 lbs; and minor changes; 260 built. Unit cost $59,950 in 1959


 * 310D
 * First model with swept vertical tail, other minor detail changes; 268 built for 1960 model year.


 * 310E
 * Military version of the 310F, designated the L-27B and later U-3B; with maximum takeoff weight of 4990 lbs; 36 built.


 * 310F
 * Model produced in 1961, with extra cabin window each side, pointed nose and other minor changes; maximum takeoff weight of 4830 lbs; 155 built.


 * 310G
 * First model with canted slimline tip tanks and optional six-seat cabin, with maximum takeoff weight increased to 4990 lbs and detail changes, 156 built in 1962.


 * 310H
 * Model produced in 1963 with maximum takeoff weight increased to 5100 lbs and enlarged cabin interior. 148 built.


 * E310H
 * Version of 310H with the 4990 lbs maximum takeoff weight of the 310G; combined total of 148 310H and E310H built.


 * 310I
 * First model with baggage compartments in rear of engine nacelles, Continental IO-470-U engines and minor detail changes; 200 built in 1964.


 * 310J
 * Model produced in 1965 with minor detailed changes and maximum takeoff weight of 5100 lbs.


 * 310J-1
 * Version of 310J type-certified in the Utility Category; with maximum takeoff weight increased to 5150 lbs; seating limited to four people instead of the 310J's six; and reduced baggage weight limit.


 * E310J
 * Version of 310J with maximum takeoff weight reduced to 4990 lbs; combined total of 200 310J, 310J-1 and E310J built.


 * 310K
 * First model with optional three-blade propellers and long 'vista view' side windows; also increased maximum takeoff weight of 5200 lbs with IO-470-V or IO-470-VO engines; 245 built in 1966.


 * 310L
 * First model with increased fuel capacity via fuel tanks inside wings and optional fuel tanks in engine nacelles, also single-piece windshield, redesigned landing gear, and minor changes; 207 built in 1967.


 * 310M
 * Revised designation for the 310E.


 * 310N
 * Model produced in 1968, with revised instrument panel and provision for optional cargo door and fuel; 198 built.


 * Model produced in 1969, with Continental IO-470-VO engines, ventral fin and a shorter nose gear leg.
 * Model produced in 1969, with Continental IO-470-VO engines, ventral fin and a shorter nose gear leg.


 * Version of 310P with turbocharged Continental TSIO-520-B or TSIO-520-BB engines producing 285 hp and maximum takeoff weight of 5400 lbs; combined total of 240 310P and T310P built.
 * Version of 310P with turbocharged Continental TSIO-520-B or TSIO-520-BB engines producing 285 hp and maximum takeoff weight of 5400 lbs; combined total of 240 310P and T310P built.


 * Last short-nose model, introduced in 1970, with maximum takeoff weight increased to 5300 lb and detailed changes, from the 401st aircraft fitted with a bulged rear cabin roof with rear view window.
 * Last short-nose model, introduced in 1970, with maximum takeoff weight increased to 5300 lb and detailed changes, from the 401st aircraft fitted with a bulged rear cabin roof with rear view window.


 * T310Q
 * Version of 310Q with turbocharged Continental TSIO-520-B or TSIO-520-BB engines and maximum takeoff weight increased to 5500 lb; combined total of 871 310Q and T310Q built.


 * Last production model, introduced in the 1975 model year, with 285 hp Continental IO-520-M or IO-520-MB engines; three-blade propellers as standard; lengthened nose containing a baggage compartment; and 5500 lb maximum takeoff weight.
 * Last production model, introduced in the 1975 model year, with 285 hp Continental IO-520-M or IO-520-MB engines; three-blade propellers as standard; lengthened nose containing a baggage compartment; and 5500 lb maximum takeoff weight.


 * T310R
 * Version of 310R with turbocharged Continental TSIO-520-B or TSIO-520-BB engines; combined total of 1,332 310R and T310R built.


 * 310S
 * 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
 * First model with canted fuel tanks and minor changes; 47 built.


 * 320B Skyknight
 * First model with nacelle baggage lockers, minor changes; 62 built.


 * 320C Skyknight
 * Model with a longer cabin, optional seventh seat and minor changes; 73 built.


 * 320D Executive Skyknight
 * Model with reshaped rear windows and 285 hp TSIO-520-B engines; 130 built.


 * 320E Executive Skyknight
 * Model with pointed nose, single piece windshield, modified landing gear, increased takeoff weight and minor changes; 110 built.


 * 320F Executive Skyknight
 * Model with minor changes compared to 320E; 45 built.


 * L-27A
 * United States military designation for the 310A, later changed to U-3A.


 * L-27B
 * United States military designation for the 310E/310M, later changed to U-3B.


 * U-3A
 * L-27A redesignated in 1963.


 * U-3B
 * L-27B redesignated in 1963.


 * Colemill Executive 600
 * Conversion of models 310F to 310Q, replacing the engines with 350 hp Lycoming TIO-540-J2BDs driving four-bladed propellers.


 * Riley 65
 * Conversion offered for models 310 to 310G, replacing the engines with two 240-260 hp (179–194 kW) Continental O-470Ds or -470Ms.


 * Riley Super 310
 * Conversion of Cessna 310/320 by fitting two 310 hp (231 kW) Continental TSIO-520J or 520N engines.


 * Riley Turbostream
 * Conversion of Cessna 310 by fitting two 350 hp Lycoming engines.


 * Riley Rocket
 * Conversion of Cessna 310 by fitting two 290 hp (216 kW) Lycoming IO-540-A1A5 engines and more fuel capacity.


 * Riley Turbo-Rocket
 * Riley Rocket with each engine fitted with two Riley-manufactured turbochargers. Cruise speed increased from 252 mph to 302 mph.

Civil
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.


 * Argentina
 * Argentine Air Force — Cessna 310 and 320 models
 * Bolivia
 * Colombia
 * Colombian Air Force
 * Republic of the Congo
 * France
 * French Air and Space Force — 12 operated
 * Haiti
 * Haiti Air Corps
 * Indonesia
 * Indonesian Air Force
 * Indonesian Army Aviation
 * Iran
 * Madagascar
 * Air Force of Madagascar — One 310R
 * Mexico
 * Mexican Naval Aviation
 * Paraguay
 * Paraguayan Air Force
 * Peru
 * Peruvian Navy
 * Philippines
 * Philippine Air Force
 * Saudi Arabia
 * Suriname
 * Suriname Air Force
 * Tanzania
 * Tanzanian Air Force
 * United States
 * 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.
 * Uruguay
 * Uruguayan Air Force (One 310R)
 * Venezuela
 * Venezuelan Navy
 * Zaire
 * Zaire Air Force

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 Camagüey to Havana. Neither the aircraft nor the body of Cienfuegos were ever found.
 * On November 26, 1962, a Saab Scandia 90A-1, aircraft registration PP-SRA of VASP on a scheduled domestic service in Brazil from São Paulo-Congonhas to Rio de Janeiro-Santos Dumont collided in the air over Paraibuna, São Paulo, with a private Cessna 310 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 near Hendersonville, North Carolina, killing all 79 people on board the Boeing 727 and the three people in the Cessna.
 * On October 16, 1972, US Congressmen Nick Begich of Alaska, and Hale Boggs of Louisiana, disappeared over Alaska while flying in a 310C during a campaign trip.
 * On October 4, 1975, a chartered 310Q crashed on final approach to New Hanover County Airport while transporting wrestlers Bob Bruggers, Ric Flair, Johnny Valentine and Tim Woods and promoter David Crockett to a professional wrestling match in nearby Wilmington, North Carolina. Bruggers and Flair were seriously injured, while Valentine was paralyzed and the pilot subsequently died of his injuries. The aircraft was overloaded and its center of gravity was beyond the aft limit; attempting to mitigate these problems, the pilot drained fuel before the flight, causing fuel exhaustion before the aircraft reached the runway.
 * On September 11, 1981, a T310P crashed into an upper wall of the Swing Auditorium in San Bernardino, California, killing both aircraft occupants; the crash and a major ensuing fire caused severe damage to the building's roof, structural members, insulation, and about a third of the bleachers. The building was ultimately deemed beyond repair and was razed seven months later.
 * On June 29, 1989, concert organist Keith Chapman and his wife were killed when their 310Q piloted by Chapman crashed into the Sangre de Cristo Mountains of the Colorado Rockies while they were returning from a performance in California.

, the US National Transportation Safety Board has recorded 1,787 incidents for Cessna 310s since 12 January 1964. Of these, 436 were fatal.