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 there’s ice or thunder in the forecast. Pressurization is nice since clients don’t 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 don’t 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