Cessna 310R: More twin for the buck

By GUY R. MAHER

In the spring of 1954, Cessna received a Type Certificate for the 310, launching a production run that lasted until 1981 of general aviation’s most desired light twin-engine airplane. The most famous was the 1958 310B used in the TV series “Sky King.”

Through the years, the 310 evolved to become a larger, more powerful, and better performing airplane, culminating with the final variant, the 310R, which debuted in 1975.

So why, with a used plane market that has tanked and fuel prices sure to increase, are we focusing on a legacy twin engine airplane?

C310R-GM (13)smThat’s because today’s down market means you can get more plane for less money.

The new singles that push 200 knots, costing more than $500,000, or Raytheon’s $1.2 million Baron 58, can’t touch the hauling ability of the 310Rs, which are selling for well under $200,000.

The 1977 310R pictured is a good example of a clean, low-time, market-ready airplane. It’s updated with a Garmin 530, GDL-69 receiver for Nexrad weather, and GTX 330 transponder with traffic displayed on the GNS 530. A KX-155 nav/com, H.S.I., Stormscope, monochrome radar, and original 400B autopilot complete the avionics.

With a maximum takeoff weight of 5,500 pounds, useful load is 1,824 pounds. Even with topped-off tanks, cabin load is still 846 pounds. This means four 200-pound occupants and 200 pounds of baggage can fly IFR from Charlotte, N.C., to 500-plus nm destinations such as West Palm Beach, Fla., or Teterboro, N.J., with very conservative reserves.

With flexible loading potential and a big cabin, the 310R has the space for six adults and all their stuff. Baggage can be loaded in the nose compartment, wing lockers, or aft cabin area.

Of course, the best seat in the house is the front left. In that seat, this design from the 1970s still holds up for relative ease of operation.

The fuel selector for each engine is located between the two front seats. The system is simple to operate. However, it also can be the most complicated system on the airplane, especially when you factor in the various auxiliary fuel options. A little study is all that’s required to manage fuel like a pro.

On the left side wall is a convenient waterfall panel of accessory switches and circuit breakers. The most inconvenient aspect of the panel is that all engine and system gauges are way over on the right side. Monitoring these instruments takes a definitive effort in the scan.

Engine starts are a snap. Whether starting in below freezing conditions or high summer temperatures, I’ve always found the 310R to be a predictable starting airplane. Ground handling is quite easy. With a 9-foot, 2-inch wheel base and a nose gear that is vertical, taxi turns are a snap. Add a little brake and differential power and impressive tight turns can be made.

Takeoffs in the 310R are pure fun. Acceleration is brisk, thanks to the twin 285-hp Continentals. The 80 knot Vmc comes and goes quickly and lift-off occurs at 92 knots with the best twin-engine rate of climb speed of 107 knots quickly established.

Once that objective is met, cruise climb power is established, auxiliary pumps are turned off, and mixtures are adjusted.

Obstacle clearance takeoffs are performed with 15° of flaps and an initial climb speed of 85 knots. That close to Vmc, with 15° of flaps, is not the most comfortable place to be. However, the 310R establishes an excellent climb angle while blowing right past 85 as well as its safe single engine speed of 92 knots. The 310 loves to climb, and it loves to quickly get out of that low speed range.

Top of the green arcs in climb power and 120 knots indicated is a nice set-up for going to cruise altitude. I normally fly 310Rs at 250 to 500 pounds below gross and, under this scenario, I can expect around 1,500 fpm to about 6,000 feet; then 1,000 to 1,200 fpm through around 9,000 feet; and then around 800 fpm up to 12,000 feet.

I dug back into my trip logs from years past and found one particular five-day route that required 11.7 hours — some long legs, some short. True airspeeds ranged from a low of 185 knots to a high of 198 knots. All that flying consumed 280.9 gallons of fuel for a block average of 24 gph.

Even down low, the 310R gives excellent cruise performance. For example, I recently ran a short trip and stayed at 3,000 feet. At 65% power, TAS hit 175 knots with a 27.5 gph fuel flow — I lean conservatively for engine health first, economy second.

The 310, regardless of model year, is a delight to fly. The ride is solid in cruise, deftly handling turbulence. The controls are smooth and, although firm, not tiring even after a long day of flying. Control response is excellent and conventional in every manner. The first 15° of flaps can come out at 158 knots. The landing gear and rest of the flaps can come out at or below 138 knots.

The flight manual calls for a 93-knot approach speed with full flaps. This is certainly a stable speed and can help produce impressive short field landings. I have taken 310Rs into 1,800-foot runways on a regular basis. I kept one of the three 310s I used to own at a 2,500-foot grass field as well. Certainly I was light going in and coming out – using a larger paved airport nearby for times when the takeoff weight was heavy.

For more “normal” landings I like to target 100 knots and gently walk off the throttles to idle as the threshold is crossed. Very pleasing and consistent arrivals can be achieved in the 310 — especially the R model where that extended nose seems to help with a more fluid round out in the flare.

Recent recurrent training for my CFI renewal check ride in the 310R reminded me once again how decently this plane flies on one engine. Even when I opted to leave rudder trim neutral, I didn’t blow out my ACL pushing on the rudder. No piston twin is going to blow your socks off climbing on one engine, but the 310R can be depended on to give a solid climb even when heavy on a hot day as long as your technique is good. The single engine rate of climb is 370 fpm at sea level, standard conditions at gross weight. Try it at 2,000 feet and 80° and you still get around 250 fpm. Planning and proficiency is key.

THE BOTTOM LINE

Financial planning and maintenance proficiency are key as well when it comes to owning any twin and the 310 is no different.

The cost of fuel last summer was one factor in the drop of twin values. Consider, though, that any of the modern singles that can keep up with the 310 also suck some gas. Twice the engines, in the real world, means more like 30% more in fuel. For some, that’s an acceptable trade to get 310R speeds and twin redundancy with a fueled cabin load capability of much more than 300 to 400 pounds.

Next is insurance. Jon Harden, president of Aviation Insurance Resources of Frederick, Md., pointed out that if you are just transitioning into twins, “it’s going to cost — if you can get coverage at all” — for the 310. “Underwriters are friendlier to the Aztec or Seneca,” he noted.

If you have the hours and the ratings, you can insure a $150,000 310R for around $3,700. “A high timer with more time in every category can expect closer to $3,300,” he added.

When it comes to maintenance, the 310R is the easiest to care for of all 310s. Cessna changed the materials, and the exhaust in the 310R, which reduced corrosion problems, essentially leveling the playing field between the 310 and all other twins of the same era.

But what about that landing gear?

“The 310 landing gear requires detailed knowledge to keep it working correctly,” said Tony Saxton, a twin Cessna maintenance guru at TAS Aviation Inc. in Defiance, Ohio. “Rigging is crucial and is required every year or 200 hours and the Cessna maintenance manual must be followed religiously for this procedure. The vast majority of problems we see are caused by shops just doing the typical gear swing and lube during an annual — and that will eventually lead to big problems.”

In all but the earliest of models, parts availability seems to be decent simply because of the number of 310s Cessna built. Cessna also is reportedly good at providing those hard-to-find early model parts — but no one said they’d be cheap.

Owning a 310 also mandates belonging to owners groups for operational knowledge and assistance. The Cessna Pilots Association and The Twin Cessna Flyer are two must haves in your support kit.

I’ve owned two 310Rs and a 1957 310, which produced mostly wonderful ownership experiences. Of the two dozen airplanes I’ve owned over the past 31 years, I’d love most to have that ’57 310 back for one more round. But those earliest of 310s are now only viable for owners who have the skills, patience, and budget to treat them like vintage airplanes.

However, if your mission requirements justify a twin, or your discretionary budget allows it, then you’d be hard pressed to get more twin for the buck than the Cessna 310R. The systems are simple, you can work on them with basic tools, they are forgiving to fly, flexible to load, go like hell, and seem to just last and last.

In today’s buyer’s market, all this capability, speed, and beauty comes at prices never dreamed of even five years ago.

Comments

  1. Great article by Guy Maher and a pristine photo. Good work, GAN!!

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