The Cessna 335 is the unpressurized version of the Cessna 340. Less successful than the latter, the 340 is a piston engine business aircraft manufactured by the company. It joined its contemporary, the Beechcraft Duke, the only other six-seat business plane in the industry at that time.

Following the success of the 310 series, the Cessna 340 was thought to be a cabin-class development of this model. The 340 is a six-seater plane, with four passenger seats, an aisle, and an air stair door.* The tail design was based on the 310, while the wings were based on the Cessna 414. Its selling point was it’s spacious, pressurized cabin, that was the first in a light twin.

The company designed the aircraft back in 1969, but it was not until 1971 that the aircraft was delivered. One of the prototypes under testing at that time had crashed; hence, the delay in production. The 340 has three variants: the 340, 340A and the 335.

The 340 had two Continental TSIO-520-K engines, which had 285hp. These were certified by the FAA on October 15, 1971. The 340A was upgraded to a 310hp engines, and was certified November 19, 1975. This plane also featured a smaller propeller to reduce the noise of the plane. The Cessna 335 was the unpressurized version of the 340, powered by Continental TSIO-520-EB engines. These had 300hp and was certified on October 2, 1979.

The 335 was not successful in production, even when Cessna had claimed that “it was the lowest priced cabin class business twin in the market.” Only 64 aircrafts of this model had been built. The company had stopped producing 335s by 1980.

Sources:
*http://en.wikipedia.org/wiki/Cessna_340
**http://www.airliners.net/aircraft-data/stats.main?id=151