Starting from Scratch
In addition to its growing line of single-engine aircraft, Cessna realized that to compete in the postwar market it needed a twin-engine model. The company briefly considered buying Ted Smith’s Commander design but, according to Daryl Murphy “…it had a heavy and complex structure that would require an extraordinary amount of fabrication and assembly time. Cessna was a company that required assembly line efficiencies, so they realized they would have to start from scratch.”
Designers got to work on the new airframe in 1951. Specifications for the design included a rather daunting list of items: it had to fit in a 40 x 28-foot T-hangar, have good handling characteristics, operate from almost any airfield, carry five people and cruise in the high hundreds.
Daryl Murphy gives us some additional insight into design factors for the 310: “Engineers decided on the tried-and-true 23012 airfoil with both chord and thickness tapering to 23015 outboard of the nacelles and to a 23009 configuration at the tips.
“Since it would be a low-wing retractable-gear design, the stowed gear would consume most of the space in the inboard wing, and fuel would have to be located outboard of the engine nacelles. With a proposed wingspan of 36-37 feet, there was not enough room to hold the proposed fuel load there, so they borrowed an idea from contemporary jet fighters and designed torpedo-shaped tiptanks that would become the unique feature of the 310 and other future Cessna twins.
“The 50-gallon tanks had the added benefit of putting flammable fuel as far as possible from the cabin.”
Three Years in the Making
After working through these and other considerations, Type Certificate No. 3A10 was issued on March 22, 1954 for the 310. It was certified with either the Continental O-470-B or O-479M engines, Hartzell propellers and a fuel capacity of 102 gallons—51 in each tiptank. It debuted with a base price of $49,950.
There were several model changes over the years with a total of about 5,400 planes manufactured (including military models). Today, about 2,600 model 310s remain on the FAA registry. A search on ASO.com on July 6, 2012 reveals prices from $29,990 for a 1955 310 to $179,000 for a 1973 310Q.
The 310 was manufactured over a course of 26 years and proved to be a fast and reliable airplane that has a loyal following even today.
MAIN 310 VARIANTS
310: Production aircraft powered by two 240 hp (180 kW) Continental O-470-B engines; 547 built.
310A: Military version of the 310 for the United States Air Force, designated L-27A and later U-3A; 160 built.
310B: New instrument panel, O-470-M engines and minor changes; 225 built.
310C: 260 hp IO-470-D engines, increased takeoff weight and minor changes; 259 built. Unit cost $59,950 in 1959.
310D: Swept vertical tail and minor detail changes; 268 built.
310E: Military version of the 310F, designated the L-27B and later U-3B; 36 built.
310F: Extra cabin window each side, pointed nose, new tiptank shape and other minor changes; 156 built.
310G: Slimline tiptanks, six-seat cabin, an increased takeoff weight and detail changes; 156 built.
310H: Increased takeoff weight and enlarged cabin interior; 148 built.
310I: IO-470-U engines, baggage compartments in rear of engine nacelles and minor detail changes; 200 built.
310J: Minor changes; 200 built.
310K: Long “vista view” side windows, increased takeoff weight and IO-470-V engines; 245 built.
310L: Single-piece windshield, redesigned undercarriage, increased fuel capacity and minor changes; 207 built.
310M: Revised designation for the 310E.
310N: Revised instrument panel, optional fuel tanks in engine nacelles, IO-470-V-O engines and minor changes; 198 built.
310P: Shorter nose undercarriage leg, ventral fin, and optional engines; 240 built (including turbo version).
T310P: Turbocharged Continental TSIO-520-B.
310Q: Takeoff weight increased to 5,300 pounds and detailed changes including a bulged rear cabin roof, rear view window; 1,160 built.
310R: Three-blade McCauley propellers, lengthened nose with baggage compartment, 5,500 pounds (2,500 kg) takeoff weight and
285 hp IO-520-M or IO-529-MB engines (IO-529-MB engines only on serial numbers 310R1501 through 310R2140); 1,332 built.
310S: Original designation for the Cessna 320.
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.
Sources: Wikipedia, FAA.gov
“Out of the Clear Blue of the Western Sky Comes…. Sky King!”
These words opened episodes of the popular TV program “Sky King.” The show featured the adventures of Schuyler “Sky” King, owner of the Flying Crown Ranch and a pilot who used his twin-engine Cessna—nicknamed “Songbird”—to catch bad guys and evildoers. He’s aided by his niece Penny, who is also a pilot.
The first plane featured on the show was a Cessna T-50 Bamboo Bomber. Sky King aficionado Rick Plummer lists three different year models of the T-50 over the course of the show.
Starting with the 1957 season, Sky King took to the air in a Cessna 310B—and apparently used that model for the duration of the show which ended in 1959.
The show undoubtedly sparked an interest in aviation for the many young men and women who watched.