Cessna 310

Cessna 310 / 320
1965 Cessna 310J
Role	Twin-engined cabin monoplane
Manufacturer	Cessna
First flight	January 3, 1953
Primary users	General Aviation United States Air Force
Produced	1954–1980
Number built	6,321
Unit cost	US$147,750 (normally aspirated version, 1978 price)

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-engined 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 (230 kW) engines with Lycoming TIO-540 350 hp (261 kW) 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 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.