Originally designed in the 1950s by the Stinson Aircraft Company, Piper Aircraft manufactured the Apache and a more powerful version, the Aztec, in the United States from the 1950s to the 1980s. The United States Navy and military forces in other countries also used it in small numbers. The PA-23 was the first twin-engined Piper aircraft, and was developed from a proposed "Twin Stinson" design, inherited when Piper bought the Stinson Division of the Consolidated Vultee Aircraft Corporation. The prototype PA-23 was a four-seat low-wing all-metal monoplane with a twin tail, powered by two 125 hp Lycoming O-290-D piston engines; it first flew on March 2, 1952. The aircraft performed badly and it was redesigned with a single vertical stabilizer and an all-metal rear fuselage and more powerful 150 hp Lycoming O-320-A engines. Apache (ICAO code: PA23) Two new prototypes of the redesigned aircraft, now named Apache, were built in 1953 and entered production in 1954; 1,231 were built. In 1958 the Apache 160 was produced by upgrading the engines to 160 hp (119 kW); 816 were built. The Apache 160 was superseded in 1962 by the Aztec-derived Apache 235. With a 1962 price of $45,000, the Apache 235 featured the Aztec's 235 hp (175 kW) engines and swept tail surfaces (119 built). Aztec (ICAO code: PA27) An ex-United States Navy U-11A on display at the Pima Air & Space Museum The same year, Piper produced an upgraded version with 250 hp (186 kW) Lycoming O-540 engines and a swept vertical tail as the PA-23-250, and named it Aztec. The first models came in a five-seat configuration in 1959. In 1961 a longer nosed variant, the Aztec B, entered production. Later Aztecs were equipped with IO-540 fuel-injected engines and six-seat capacity, and remained in production until 1982. There were also turbocharged versions of the later models, which could fly at higher altitude. For more details, including the 19 variants of both models, click here. Specifications below are for the PA-23-250F, normally aspirated variant. Apache Aztec
