The Piper PA-23, named Apache and later Aztec, is an American four- to six-seat twin-engined light aircraft aimed at the general aviation market. The United States Navy and military forces in other countries also used it in small numbers. Originally designed as the Twin Stinson 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 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.[1] The prototype PA-23 was a four-seat, low-wing, all-metal monoplane with a twin tail, powered by two 125 hpLycoming O-290-D piston engines;[1] it first flew on March 2, 1952.[2] The aircraft performed badly, so it was redesigned with a single vertical stabilizer and an all-metal rear fuselage and more powerful 150 hpLycoming O-320-A engines.[1]
Two new prototypes of the redesigned aircraft, now named Apache, were built in 1953[1] 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.[citation needed]
The Apache 160 was superseded in 1962 by the Aztec-derived Apache 235.[citation needed] With a 1962 price of $45,000, the Apache 235 featured the Aztec's 235 hp (175 kW) engines and swept tail surfaces[3] (119 built).
In 1959, 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.[1] The first models came in a five-seat configuration. In 1961, a longer-nosed variant, the Aztec B, entered production.[1] 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.
PA-23 Apache in National Air and Space MuseumApache on amphibious floatsPA-23 Apache 235 fitted with the Aztec-style square fin and rudderAn Apache with Geronimo tail modificationPiper Aztec C with de-cowled Lycoming IO-540-C4B5 engines
PA-23 Twin-Stinson
Original designation of the Piper PA-23 Apache
PA-23 Apache
Initial production version, 2047 built (including the Apache E, G and H)
On 21 March 1964, a Piper PA-23-160 Apache (G-ASHC) crashed on its approach to the Aintree racecourse, near Liverpool, England, killing all 5 on board. The flight had taken off from Luton Airport and included broadcaster Nancy Spain, who was covering the Grand National, and her friend Joan Werner Laurie, who was learning to fly. The CAA accident report stated that passenger interference could not be ruled out as a cause of the accident.[12][verification needed]
On 18 April 1974, Aztec G-AYDE collided with Court Line Flight 95, a BAC One-Eleven, at London Luton Airport after the pilot of the Aztec entered the active runway without clearance. He was killed and his passenger was injured. All 91 people on board the One-Eleven successfully evacuated after the takeoff was aborted.
On 29 November 1975, retired Formula One racing driver and Embassy Hill team owner Graham Hill was piloting a Piper PA-23-250 Turbo Aztec D, marked as N6645Y,[a] from Circuit Paul Ricard, France, to London, United Kingdom.[15] His passengers were Embassy Hill race driver Tony Brise, team manager Ray Brimble, designer Andy Smallman, and mechanics Terry Richards and Tony Alcock. While on approach to land at Elstree Airfield, Hertfordshire, shortly before 10 pm, the aircraft hit trees on a golf course at Arkley, Hertfordshire in thick fog. The ensuing crash and explosion killed everyone on board.[16][17]
On 15 April 1978, Hollywood stunt flyer Frank Tallman was ferrying a Piper Aztec from Santa Monica Airport, California, to Phoenix, Arizona under visual flight rules when he continued the flight into deteriorating weather, a lowering ceiling, and rain. He struck the side of Santiago Peak in the Santa Ana Mountains near Trabuco Canyon at cruise altitude, dying in the ensuing crash.[18][19]
^Although marked with U.S. registration and carrying matching and unexpired registration documents, the aircraft's U.S. registration had been canceled after it was exported to the Bahamas, and its new owners had not re-registered it.[14]
Bridgman, Leonard (1952). Jane's All The World's Aircraft 1952–53. London: Sampson Low, Marston & Company, Ltd.
Fontanellaz, Adrien; Cooper, Tom; Matos, Jose Augusto (2020). War of Intervention in Angola, Volume 3: Angolan and Cuban Air Forces, 1975-1985. Warwick, UK: Helion & Company Publishing. ISBN978-1-913118-61-7.
Hagedorn, Daniel P. (1993). Central American and Caribbean Air Forces. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd. ISBN0-85130-210-6.
Peperell, Roger W; Smith, Colin M. (1987). Piper Aircraft and their Forerunners. Tonbridge, Kent, England: Air-Britain. ISBN0-85130-149-5.
Angola[5]
Argentina
Bolivia
Brazil
Cameroon
Colombia
Costa Rica
Cuba
El Salvador
Guatemala
Honduras
Haiti
Madagascar
Mexico
Nicaragua
Spain
Paraguay
Papua New Guinea
Uganda
United States
Venezuela
Uruguay
Media related to Piper PA-23 Apache at Wikimedia Commons
