Used Aircraft Guide: Cessna 340/340A

A fast, pressurized cabin-class twin thats still one of the best step-ups from a high performance single.


Although airplanes are often sold as business and transportation tools, the reality of ownership falls short of the ideal. While either lack the range, the carrying capacity or the ability to deal with real-world weather, thus an airline or a charter outfit gets the call.

A serious business airplane needs a decent cabin, credible speed and the ability to


hack it when theres ice or thunder in the forecast. Pressurization is nice since clients dont want to spend several hours with a plastic hose stuck up their noses. Family members arent that keen on it, either.

Enter the Cessna 340. Although not without its shortcomings, most notably certain loading limitations and an overly complex fuel system, the 340 is an impressive, flexible and capable airplane.

Model History

The 340 owes its existence to the boom days of general aviation during the late 1960s and early 1970s when the twin market was stratified and still developing. At the entry level, you had Twin Comanches, Apaches, Aztecs, Baron and the Cessna 310. At the upper end, the ritzy cabin-class Cessna 421, Beech Duke and Piper Navajo met the needs of well-heeled owners who could afford megabucks for an airplane.

The 340 arrived in 1972 to fill niche in between: a modest cabin class with an affordable price tag. It was a lower-cost alternative to the Cessna 414, which had arrived in 1970.

Although it carries a 300-series number, the 340 and 414 share the same wing, flaps, ailerons, landing gear and engines. The 340 has an air-stair door, thus you dont need a ladder to get into it, as some have jokingly complained about the long-legged Cessna 310. The 340 carries less than the 414, but its faster on the same fuel burn.

From 1972 through 1975 the engines were Continental TSIO-520Ks, which produce 285 HP at 33 inches manifold pressure from sea level to 16,000 feet. However, most of the K engines in early 340s have been converted to Js or Ns.

The TSIO-520J engine, used on early 414s, produces 310 HP at 36 inches manifold pressure. The N engine, installed on later 414s and 340As, produces 310 HP at 38 inches.

The major difference between the K engine and the J and N variants is that the latter are equipped with intercoolers, which wash the heat out of the induction air as it flows to the cylinders. This yields better power and efficiency without stressing the jugs, something thats good for longevity.

The N engines produce their rated 310 HP up to 20,000 feet and provide higher cruise speeds and better climb and single-engine performance. Three-blade McCauley propellers, formerly an option, also became standard equipment in 1976; earlier 340s came with two-blade McCauleys.

Cessna 340s are prized for being all-weather machines but aircraft certified for flight into known icing conditions, when properly equipped, came only in 1977. The following year, a maximum ramp weight of 6025 pounds was approved, and max


weight for takeoff and landing was set at 5990 pounds for the 340A, compared with 5975 pounds for the 340. The last significant change in the line came in 1979, with the switch to TSIO-520NB engines (the B denotes a heavier crankshaft). Subsequent modification of cylinders, valve lifters and piston pins by Continental increased TBO of the NB engines from 1400 to 1600 hours in 1983.

But Cessna didnt build any 340As (or much of anything else) that year and after putting together a scant 17 of the airplanes in 1984, production was terminated for good, with a total of about 1297 aircraft made. Some 872 are still registered.


The pressurization system is the same as those found in Cessnas 400-series twins, with a maximum differential of 4.2 PSI providing an 8000-foot cabin up to 20,000 feet. Above that, the cabin climbs with the airplane.

Cessna offered an automatic pressurization control, which activates and deactivates while climbing or descending through 8000 feet, but more buyers opted for the variable-control system. The variable system maintains a sea-level cabin up to 9000 feet, then delivers the pilot-selected cabin altitude until a 4.2 PSI differential is reached.

As pressurization goes, the 340 is relatively easy, requiring just a quick check and set for each flight. The pilot merely dials in field elevation plus 500 feet before takeoff and landing and selects desired cruise cabin altitude on initial climb. The rest is simply monitoring the system to make sure its delivering as commanded.

While the pressurization is easy, the same cant be said for the fuel system. Start with the 100-gallon-usable tip tanks which are the mains in this airplane. Add up to four auxiliary wing tanks, two holding 40 gallons, the other two holding 23 gallons. Throw in locker tanks, which add another 40 gallons. Thats up to 203 gallons in tanks peppered throughout the length of the wings.

Where things get tricky for the uninitiated is which tank to use when. Use the mains, alone, for takeoff and landing. The engines can feed directly from the auxiliary tanks, but fuel in the lockers has to be transferred to the mains, which are the tip tanks. You have to make room in the mains first, otherwise youll vent the pumped fuel over the side.

And if you have only one locker tank (common on 340s), remember to use crossfeed; dump all 120 pounds from a locker into one tip tank, and the imbalance will be enough to upset even your autopilot. Unfortunately, Cessna never got around to simplifying the fuel systems in its 300-series twins (Crusader excepted) as it did in most of the 400s. Calling the tip tanks mains has its own issues. Ramp attendants have filled the wrong tanks (“Just top off the mains ….”). Transitioning pilots have switched to the aux tanks thinking they were drawing from the tips, and vice versa.

Despite this, the 340 hasnt suffered an inordinate number of fuel-related


accidents. Jerry Temple, an aircraft dealer specializing in the 340, says, “The fuel system is no big deal. I prove it twice a month to new twin Cessna owners. It can be mastered in one 3 hour cross country.

While known ice certification came in 1977 and up, the majority of 340s have what is called full deice. This usually mean boots on the wing and tail (with the exception of the wing stubs), heated props and alcohol spray for both sides of the windshield. This is adequate for many 340 owners. The few 340s out there with hot props only are tough to sell, but can be ideal for owners warmer locations.

Air conditioning might be the factory system, which requires the right engine be running to get cool air. Parts for this system can be challenging to get. The Keith System, also called JB Air by many, is electric and can be powered by a ground APU, although in the real world of FBOs, a 340 rarely gets the APU. Support for the Keith system is good.


The 340 is a high flyer, with a service ceiling of nearly 30,000 feet. But most owners wisely operate in the high teens to mid-20s, where the airplane can be expected to true between 190 and 205 knots on about 30 gallons per hour at 65 percent power, and 200 to 217 knots on 32 to 34 GPH using 75 percent power.

Rate of climb at sea level is a respectable 1650 FPM, but climb performance tapers above 20,000 feet to a dawdling 300 to 400 FPM in the mid-20s. Not bad as twins go, but no turboprop, either.

The 340s claimed single-engine rate of climb is 315 FPM, better than the 414 (290 FPM), Beech P58 Baron (270) and the Piper 601P (240) and 602P (302) Aerostars. Single-engine minimum control speed is 82 knots. Stall speeds are 79 knots, clean, and 71 knots in landing configuration.

Not all twins of the 340s days have accelerate-stop and accelerate-go performance tables but, to Cessnas credit, the 340 does. Under standard conditions, a 340 that loses an engine at lift-off speed (91 knots) can be brought to a full stop within 3000 feet of brake release. The POH also indicates that should a pilot decide to fly after losing one on lift-off, the airplane will clear a 50-foot obstacle after traveling less than 4000 feet over the ground after brake release (assuming the pilot does everything right).

The performance figures above are for 340s with 310-HP engines. Those that still have 285-HP K engines (if any) are nearly 20 knots slower in cruise, use roughly 200 feet more runway for takeoff and climb 1500 FPM on both engines, 250 FPM on one.

Handling and Payload


Cessnas big twins have a reputation for being comfortable and easy to handle and the 340 fits that mold, although not entirely without warts. The airplane owes its speed to a relatively slick airframe and because it has flap and gear operating speeds that are on the low side, it can be a handful to go down and slow down at the same time.

For example, flaps can be extended 15 degrees at 160 knots (the limit is 156 knots for the first 300 airplanes built) to help slow the airplane to max gear-extension speed, a pitiable 140 knots. But slowing the airplane to 160 knots without stressing the engines can be a problem, if you believe in the shock cooling genie. Owners say descents and approaches require planning and occasional persistence with ATC if a slam dunk is in the offing.

Once the airplane is slowed down with gear and flaps deployed, however, it tends to sink like a rock, and some power must be maintained right into the flare. This is due in part to the split flaps, which are great for drag, but not so good for lift.

Entering the airplane through the luxurious airstair door gives a big-iron feel. But for the pilots, that wears off quickly when they have to squeeze through a narrow (seven-inch) opening to their seats. Once youre seated, the cabin is quite comfortable up front. The 340s cabin is 46.5 inches wide and 49 inches high, about the same size as an Aerostars and 4.5 inches wider than a P-Barons.

If owners have any consistent complaints about the 340 line, they relate to lack of payload. Load enough gas for a 4.5-hour flight with reserves and you can take along only two passengers and their bags. Fill the seats with 170-pound FAA clones and pack away their regulation 30 pounds of baggage each and you can carry enough fuel for less than two hours of flying.

Considering the payload limitations, the baggage space in the 340 seems a cruel joke. Among the cabin, nose and locker compartments, theres a cavernous 53 cubic feet of space in which a maximum of 930 pounds can be crammed. That is, however, the maximum. Most 340s have at least one fuel tank occupying a locker, and nose baggage compartment space typically is compromised by avionics gear.

The installation of vortex generators, however, brings a 300-pound gross weight bump. Considering an entire VG kit weighs about as much as the air in your tires, its about as close to a free lunch as you can get. If youre considering a 340, by all means consider vortex generators.


Like any high-performance airplane, a 340 wont tolerate skimpy maintenance. If


rebuilt engine prices in the $45,000 range (times two), annual inspections at several thousand dollars and operating expenses of $400-550 an hour curl your toes (as they do ours), the 340 is not the aircraft for you. While some owners reported annuals in the $5000-dollar range, Jerry Temple tells prospective buyers to expect $10,000 to $15,000 for annual inspections.

Owners we spoke with overwhelmingly agree the annual must be done by a shop with twin Cessna expertise. TAS aviation in Defiance, Ohio, was singled out by a few owners.

But those with the budget should get their moneys worth out of this airplane. Some things to watch out for: First, there are the TSIO-520 crankcases, which have a history of cracking. In mid-1976, Continental switched to heavier cases, which helped a bit but certainly provided no panacea. A couple of knowledgeable sources estimated that about two-thirds of the engines flying in 340s right now probably are cracked in one place or another.

But not all cracks are critical and theres a general sense that catastrophic engine failures caused by crankcase cracks are on the decline. All big-bore Continentals have a modest predilection for cracked cylinders and heads.

Cracked and blown-out cockpit windows were the subject of several reports, as were cracked Bendix mag housings and distributor blocks, loose horizontal and vertical stabilizer attach bolts, and cracked waste gate couplings.

As far as ADs go, the 340 is neither the best nor the worst. AD 2000-01-16 requires repetitive inspection, repair or replacement of exhaust components in a range of Cessna twins, not just the 340. This AD was issued in response to cracks/failures that led to catastrophic fires. AD-97-0-13 requires replacement of certain hydraulic, oil and fuel hoses while another, 88-03-07, requires inspection of fuel crossfeed lines for chafing and modification of firewall stiffener flanges and fuel lines. AD 87-23-08 calls for ultrasonic inspection of the crankshafts, as does 97-26-17. Speaking of crankshafts, some 340s were involved in the Continental crankshaft recall of 2000. The logbooks should reflect this as AD 2000-08-51.

AD 96-20-7 calls for repetitive inspections of the Janitrol cabin heater while 96-12-22 requires repetitive inspections of the oil filter adapters. 95-24-5 deals with repetitive prop inspections and 90-2-13, a type-specific directive, called for replacement of the main landing gear inner barrel bearings.


One important directive to check for is 82-26-05, which requires visual checks for cracks in the rudder balance weight rib every 100 hours until a new rib is installed. Such cracks have been the subject of numerous service difficulty reports.


Temple says his typical buyer has a few hundred hours in high performance singles, but insurance is usually obtainable at a reasonable price. The typical requirement is 25 hours dual in the aircraft and attendance at an insurance-approved school, usually with simulators and insurance-approved instructors, such as SimCom. Annual recurrent training is usually required.

Low-time owners also might not get more that $1M with per-seat limits of $100,000 until they have accumulated more 340 time.

Temple also says that now is a good time to be a 340 buyer as prices are at all-time low. The savings can pay for more dual instruction for a low-time pilot, or allow for expensive avionics upgrades. However, Cessna 340 prices are slowly climbing.

Mods, Owner Groups

The 340 fleet has been a popular model for engine modifications performed by RAM Aircraft Corp. Their mods increase the number of powerplant options to five: the standard TSIO520-NBs (310 HP), the RAM Series IV (325 HP), the RAM Series VI and VII (335 HP each) and the stock 310-HP engine with American Aviation Intercoolers. This last combo provides performance similar to the 325-HP RAM IV. RAM packages include a seventh stud on crankcase cylinder pads, which reduces the stresses in these areas that often cause cracks. (Contact RAM at or 254-752-8381.)

Improved turbocharger intercooling systems are available from American Aviation and are highly recommended by owners. The installation includes ram-air inlet ducts under the engine nacelles and more efficient (American says 28- to 70-percent more efficient) heat exchanger cores. The company says its system cuts the temperature of air entering the engine from about 170 degrees to 80 degrees, improving rate of climb by up to 300 FPM and adding up to 15 knots in cruise. (Contact American at: or 800-423-0476.)

A STOL mod for 340s was offered by Sierra Industries, and included installation of Robertson-designed Fowler flaps and a trim spring that precludes the need to retrim the elevators when the flaps are raised or lowered. Sierra says the mod decreases accelerate-stop distances by 40 percent and improves short-field performance about 15 percent. Although still supported, the mod isnt available for new installations. Contact Sierra at or 888-835-9377.

Precise Flight makes speed brakes for the Cessna 340. Theyre of novel design and project into the airstream from a snug enclosure at the aft end of the engine nacelles. Contact Precise Flight at or 800-547-2558.

Cessna 340 owner Philip Mattison told us of his switch to four-blade MT composite props that increased climb rates by 200 FPM and cruise speeds by seven knots as well as giving cooler CHTs and smoother operation. (He also says hell cut anyone a deal on a nice set of used Q-Tip Hartzell props for a 340 or a 414.)

Its rare to find a 340 without the aforementioned vortex generators, which essentially eliminate Vmc, give great control at low airspeeds and add 300 pounds to the gross weight. If you do find one, VGs are available from Micro Aerodynamics, Pacific Northwest Aero LLC, through RAM, as part of the companys speed mod kits and through Boundary Layer Research. Micro Aerodynamics is at and 800-677-2370; Pacific Northwest is at and 541-388-9902; Boundary Layer Research is at and 800-257-4847. Robertson STOL kits are still available, but the installation cost is usually prohibitive. If you need this, find a 340 with it already installed.


As for owner groups, there are two: the Twin Cessna Flyer at and the Cessna Pilots Association at or 805-922-2580. TCF also offers operations seminars that are highly regarded by owners. According to Jerry Temple, the TCF $65 dues is “the best dinner bill you will ever spend.”

Owner Comments

I have owned two 340As in the past 20 years, interspersed with a variety of Beech Barons. I have enjoyed the speed and flexibility of flying a turbocharged, pressurized twin Cessna for a total of 10 years.

Operating costs averaged $224/hour for the first airplane (owned in the 90s) and $493/hour for the second (currently owned). This doesnt include additional major expenses of an engine replacement (about $30,000), a VG kit ($4617) or Flight Safety initial training ($4350).

Flying was a lot cheaper in the 90s, partly because the fuel cost averaged $74/hour versus $145/hour. Also, despite now having 4000 hours total time, 1100 in 340s, my insurance costs doubled. My yearly flight time is also less, which drives up that hourly cost.

Eugene C Fletcher,
Louisville, KY

Ive been flying a 1980 340A with Ram VI engines and Robertson STOL for about nine years and over 2000 hours. Its comfortable and with properly syncrophased engines its quiet enough that headsets arent required, though they are nice.

We typically dont carry more than five and then only with little baggage. With only two you can fill the tanks (183 gal) and go from Southern California to Florida with one fuel stop. It typically takes two stops for the return trip. We have carried six with a light fuel load, but dont plan on flying more than a couple hours or taking much baggage.

We typically plan 207 knots with a 35-36 GPH fuel burn at 17,500 feee. You can add about 1.8 knots for each 1000 feet above that. The 340 with STOL at standard conditions needs about 1300 feet to land over a 50-foot fence and about 1800 feet to take off over the same fence. So it comfortably operates out of 2600-foot fields, but about 3200 feet is a balanced field.

With the Ram VI and STOL, the 340 picks up an additional 400 pounds of payload, so a typically equipped 340 with 183 gallons of fuel could carry about 750-800 pounds of payload.

Greg H.,
Reno, Nevada

I have owned a 1979 Cessna 340A for the past 11 years, and it has worked out so well I have yet to come up with a reason to change to a different airplane. The two aircraft I owned prior to the 340 were a Cessna 425 (Conquest I), and a Cessna 303 (Crusader), each of which I owned for a lesser period of time.

The RSTOL conversion with RAM VGs drops VMC speed down well below a stall, and opens up just about any airport where you would feel comfortable operating a stock Cessna 206. The only disadvantage of the RSTOL modification is that it precludes aftermarket speed brakes.

The RAM VI version that came with my airplane produced about 210 knots at FL200 burning 38-40 GPH total. The RAM VII conversion I installed at TBO runs about 30 degrees cooler and is 10-15 knots faster on the same fuel.


One of the frequently overlooked advantages of a pressurized piston airplane, compared to a turbine aircraft, is the ability to fly at lower altitudes, when headwinds dictate, with only a modest difference is TAS, and actually a slight decrease in fuel burn. When winds at altitude are not favorable, I generally plan on 180 knots in the 8000- to 10,000-foot range with about 36 GPH fuel flow.

The airplane best fits pilots and passengers who are well under 200 pounds, and less than 6 feet tall. If I was larger than that, I would probably buy a 414 instead of a 340 and just fly 15-20 knots slower.

Kevin E. Ware,
Mount Vernon, Washington

The Twin Cessna Flyer has represented 340 owners since 1988. The airplane has never been a better value as its a buyers market and bargains abound.

One reservation people have in switching from, say, a five-year-old Cirrus to a 35-year-old 340 is maintenance cost and downtime. A well-maintained older airplane can be every bit as reliable as a newer airplane. The 340 will definitely cost more to maintain. But one in tip-top shape can be as reliable as any airplane on the market-new or old.

On the other hand, a “bargain” airplane can be a financial nightmare. Corrosion is a big concern. The buyer who thought he had the perfect airplane gets hit with a bill of 25 percent of the value of his airplane on the first annual. These airplanes simply must be maintained by a knowledgeable shop. When buying, a pre-buy by a shop that specializes in twin Cessnas is a must.

The electro-mechanical landing gear on the 340 must be maintained strictly according to Cessnas instructions. That means re-rigging it every year or 200-hours whichever comes first. Its an eight-hour job start to finish and many shops dont do it. This is asking for trouble.

Insurance companies will typically require initial training at SimCom or FlightSafety plus 25 to 50 hours with a safety pilot in the right seat. Thereafter, annual simulator sessions are usually required. We have had members with as little as 400 hours total time transition to a cabin-class twin Cessna. It can be done if the owner is sufficiently motivated.

What we hear most often from the new owners is how much they love the pressurization. They no longer have to cajole their family to wear oxygen cannulas. They now routinely fly in the flight levels where the airplane is faster, the airspace less crowded and its easier to circumnavigate the weather. Its a new world for them.

The two long-term concerns for 340 owners are Cessnas Supplemental Inspection Document program (SIDs) and fuel availability, given the likely phase-out of 100 LL. SIDs are the industrys way of addressing the aging GA aircraft fleet and will likely affect all legacy GA aircraft, not just twin Cessnas. No one has a crystal ball, but the conventional wisdom is that the FAA will continue to address specific safety concerns via ADs and not resort to the broad-brush approach of mandatory SIDs.

The 340 can fly four to six people at up to 200 knots for 800 miles with the security of a second engine-for a purchase price of $300,000 or less. For many people, the 340 is the perfect airplane for their mission.

Bob Thomason (President TCF),
Charlotte, North Carolina

Special thanks to Jerry Temple for his background information for this article, and Remy Blanchaert Jr. for his photos.