Piper PA-23


The Piper PA-23, named Apache and later Aztec, is an American four- to six-seat twin-engined general aviation light aircraft, used also in small numbers by the United States Navy and military forces in other countries. Originally designed as the Twin Stinson in the 1950s by the Stinson Aircraft Company, it was produced as the Apache and a more powerful version, the Aztec, by Piper Aircraft in the United States from the 1950s to the 1980s.

Design and development

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 poorly, so 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

Two new prototypes of the redesigned aircraft, named Apache, were built in 1953 and entered production in 1954; 1,231 Apaches were built. In 1958, the Apache 160 was produced with upgraded 160 hp engines; 816 were built.
The Apache 160 was superseded in 1962 by the Aztec-derived 235 hp Apache 235. With a 1962 price of $45,000, the Apache 235 featured the Aztec's engines and swept tail surfaces.

Aztec

In 1959, Piper produced an upgraded version with 250 hp 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 1961, a longer-nosed variant, the Aztec B, entered production. Later Aztecs were equipped with Lycoming IO-540 fuel-injected engines and six-seat capacity, and remained in production until 1982. Turbocharged versions of the later models could fly at higher altitudes.
The United States Navy acquired 20 Aztecs, designating them UO-1, which changed to U-11A when unified designations were adopted in 1962.
In 1974, Piper produced a single experimental PA-41P Pressurized Aztec concept. This concept was short-lived, however, as the aspects of the Aztec that made it so popular for its spacious interior and ability to haul large loads did not lend themselves well to supporting the sealed pressure vessel required for a pressurized aircraft. The project was scrapped, and the one pressurized Aztec produced, N9941P, was donated to Mississippi State University, where it was used for testing purposes. In 2000, N9941P was donated to the Piper Aviation Museum in Lock Haven, Pennsylvania, on the condition that it never be flown again. It is now there on display.

Variants

Apache

;PA-23 Twin-Stinson
;PA-23 Apache
;PA-23-150 Apache B
;PA-23-150 Apache C
;PA-23-150 Apache D
;PA-23-160 Apache E
;PA-23-160 Apache G
;PA-23-160 Apache H
;PA-23-235 Apache 235
;Seguin Geronimo

Aztec

;PA-23-250 Aztec B
;PA-23-250 Aztec C and Aztec C Turbo
;PA-23-250 Aztec D and Aztec D Turbo
;PA-23-250 Aztec E and Aztec E Turbo
;PA-23-250 Aztec F and Aztec F Turbo
;U-11A
;UO-1
;C-26
;PA-41P Pressurized Aztec

Operators

Military operators

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  • Fuezas Aéreas Ejército de Cuba
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; Uruguay
;*Uruguayan Air Force

Accidents and incidents