The 310: Cessna’s Six-Seat “Learjet with Props”

Flying the Cessna 310 is, on the other hand, a pleasure. One of Cessna's great triumphs through the decades has been the success in making transitions up through the line relatively painless for pilots. That means the 310 flies like other Cessnas, with the caveats about its greater weight and speed taken into account. Pitch response is heaviest, roll the lightest, with generally good stick force per G and longitudinal stability. Pilots coming from other light twins will recognize the 310's as a large step up; it feels like a much larger, more substantial airplane than, say, an Apache or Travel Air. As for those moving up through the Cessna line, a 210 pilot will most definitely notice the 310's heavier controls, higher wing loading, and greater approach and landing speeds. It is a bigger jump from the complex single into the 310 than it is for, say, a pilot moving from a Bonanza to a Baron

Through its 28-year production span, the 310 evolved from a five-seater with pressure-carbureted engines to a high- flying turbocharged six-placer with known-icing certification. Cessna's landmark twin also begat a larger turbocharged model, the 320, in 1963, and provided the basis for the pressurized 340.

The Cessna 310R grosses only 5500 pounds, and has a power loading of just under 10 pounds per horsepower, a virtual guarantee of excellent climb. Cessna’s official climb spec is 1660 fpm, but if you’re flying light, you can often beat that number by several hundred fpm.

Speed has always been a strong 310 selling point, for good reason. With the 240-hp engines, the 310 will turn in cruise speeds of 183 knots (70-percent power at 7,500 feet, burning 25 gallons per hour total) and climb with both engines at better than 1,600 fpm from sea level. More weight in later models about makes up for the extra power: A 260-hp-a-side Q model turns in 186 knots (71 percent at 7,500 feet, on 26.5 gph) and climbs at 1,495 fpm; not bad considering the Q's 600-pound higher maximum gross weight. Finally, the 285-hp versions will do just over 190 knots on 29 gph.

Naturally, the turbocharged 310s are the quickest, showing 198 knots at 10,000 feet (on 74 percent and 31 gph) and 220 knots at 20,000 feet with the same settings. All the T310s come with Garrett turbochargers and automatic wastegates and are conservatively boosted. Where some versions of the TSIO-520 have been pushed to 325 hp, the 310's engines are practically loafing at 285 hp. Maximum boost for a sea-level takeoff is a moderate 32 inches. However, the turbos are relatively small, and power is down to 55 percent by 25,000 feet at the maximum recommended cruise rpm of 2,350. Operators say the T310s work best in the high teens.

The turbocharged version does even better, especially on nonstandard days with warm temperatures. By 1981, turbos had taken on legitimacy and reliability unknown on the earlier models, and some two-thirds of the final year’s production of 310s mounted blowers under the bonnets. Maximum fuel capacity on the 310 is 203 gallons, and pilots willing to climb high and throttle back to long range cruise can see 1400 nm between pit stops. This makes one stop, transcontinental flights possible between any two points in the contiguous U.S. For those folks who prefer not to fly slowly in fast airplanes, range is closer to 1000 nm at 75 percent.

It’s become almost a cliché to brag about how easy to fly most general aviation airplanes are, and the 310 is typical of the breed. The original premise of storing fuel far out on the wingtips was a bow to crash-worthiness. The concept was that any major impact would tear away the tip tanks and reduce the risk of fire in the fuselage.

Another accidental consequence, however, was a tendency to Dutch roll with any abrupt aileron input. Having 300 pounds of fuel stored at the end of such a long moment arm imparted inertia to the wings if you initiated a quick roll input. It wasn’t a major control problem – just a minor glitch to be aware of.

Landings were stereotypical twin. Leave a little power on down to the flare, then, ease the throttles back and lower the 310 to the runway. Crosswind manners were similarly benign in either the crab or wing down solution.

Technically, Cessna’s 310 was replaced by the Crusader with a big cabin and an airstair door. It barely mattered, however, as Cessna CEO Russ Meyer shut down all piston production in 1986 and resumed with only three models, all singles, in the late 1990s.

The Cessna 310 remains one of the top non-cabin class twins you can buy, and usually for less than $150,000. Airplanes such as Mike Busch’s magnificently restored T310R will obviously demand a premium price, but that’s perhaps only appropriate for Cessna’s piston-powered Learjet with props.

According to owners and 310 support groups, parts are readily available for the airplane, although, as is true with any model these days, the costs can be dear. Fortunately, aside from the gear troubles noted earlier, there doesn't seem to be any one recurring trouble spot with the 310s. That's actually a bit amazing, considering the overall age of the fleet and the complexity of the machines.