Piper Aztec

infobox Aircraft
name = PA-23 Apache/Aztec
type = Twin-engined light piston utility
logo =
manufacturer = Piper Aircraft

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caption = PA-23 Aztec
designer =
first flight = 1952
introduction = 1954
retired =
status =
primary user = United States Navy
more users =
produced = 1952-1981
number built = 6,976
unit cost =
developed from = Twin Stinson
variants with their own articles =

The Piper PA-23, named Apache and later Aztec, was an American twin-engined monoplane, the first twin-engine aircraft built by Piper Aircraft.

Originally to be named the "Twin-Stinson" and designed as a four-seater low-wing all-metal monoplane with a twin tail, the prototype first flew 2 March 1952. The prototype was then named the PA-21 to conform to Piper's numerical nomenclature [http://www.airwar.ru/enc/la/pa21.html] It was redesigned with a single vertical stabilizer and an all-metal rear fuselage and renamed to Apache 150 when it entered production in 1954; 1,231 were built. In 1958, the Apache 160 was produced by upgrading the engines to 160 hp (119 kW), and 816 were built before being superseded by the Apache 235, which went to 235 hp (175 kW) engines and swept tail surfaces (119 built).

Declining sales of the Apache prompted the redesign dubbed PA-23-250 Aztec, with 250 hp (186 kW) Lycoming. The first models were delivered with O-540 Lycoming carburetor engines. These first models came in a five-seat configuration which became available in 1959. The later models of the Aztec were equipped with IO-540 fuel-injected engines and six-seat capacity, and continued in production until 1982. There were also turbocharged versions of the later models, which were able to fly at higher altitudes.

Among other light twin-engined airplanes of its generation, the Aztec was known for its good load hauling, long endurance, stable handling, and respectable single-engine performance, at the cost of higher fuel consumption and a draggier (slower) airframe. Part of the drag was due to use of the same basic wing design (albeit with substantially different dimensions and construction) as the Piper Cub series of aircraft. The Piper Cub airfoil gave the Aztec superior short field operation characteristics at the price of lower performance at cruising speeds.

The US Navy acquired 20 Aztecs, designating them UO-1, which changed to U-11A when unified designations were adopted in 1962.

Variants

;PA-23 Apache:Initial production version, 2047 built (including the Apache E, G and H).;PA-23-160 Apache E:PA-23 powered by two 160 hp O-320-B engines.;PA-23-160 Apache G:PA-23 with longer internal cabin and extra window.;PA-23-160 Apache H:Apache G with 0-320-B2B engines and minor changes.;PA-23-235 Apache 235:Aztec with 5 seats and 235 hp O-540 engines, 118 built.;PA-23-250 Aztec:Apache G with modified rear fuselage, new fin and rudder and 250hp Lycoming O-540-A1D engines, 4811 built (including sub-variants);PA-23-250 Aztec B:Aztec with longer nose for a baggage compartment, six-seats, new instrument panel and changes to systems.;PA-23-250 Aztec C:Aztec B with either IO-540-C4B5 engines or turbocharged TIO-540-C4B5 as an option, also modified engine nacelles and modified landing gear.;PA-23-250 Aztec D:Aztec B with revised instrument panel and controls.;PA-23-250 Aztec E:Aztec D with longer pointed nose and a single piece windshield.;PA-23-250 Aztec F:Aztec E with improved systems and cambered wingtips and tailplane tip extensions.;U-11A:United States Navy designation formerly UO-1.;UO-1:United States Navy designation for PA-23-250 Aztec with additional equipment, 20 delivered later re-designated U-11A.

Military Operators

; ARG; BOL; CMR; COL; CRI; ESA; MDG; MEX; ESP
* Spanish Air Force
** Escaudrón 912
** Escuadrilla de Enlace 905; USA
* US Navy; VEN

pecifications (model E, normally aspirated)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=
crew=one, pilot
capacity=pilot plus 5 passengers (3 in the early models)
payload main=
payload alt=
length main= 31 ft 3 in
length alt= 9.51 m
span main= 37 ft 2 in
span alt= 11.3 m
height main= 10 ft 4 in
height alt= 3.14 m
area main= 208 ft²
area alt= 19.3 m²
airfoil=
empty weight main= 3,300 lb
empty weight alt= 1500 kg
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 5,200 lb
max takeoff weight alt= 2360 kg
more general=
engine (prop)= Lycoming IO-540-C4B5
type of prop=
number of props=2
power main= 250 hp
power alt= 186 kW
power original=
max speed main=210 mph
max speed alt= 182 knots, 340 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 1,200 miles
range alt=1042 nm, 1,900 km
ceiling main= 20,000 ft
ceiling alt= 6100 m
climb rate main= 1,500 ft/min
climb rate alt= 460 m/min
loading main=25 lb/ft²
loading alt=120 kg/m²
thrust/weight=
power/mass main=10 lb/hp
power/mass alt=3.38 kg/kW
more performance=
armament=
avionics=

ee also

aircontent
related=
Helio Twin Courier

similar aircraft=
* Cessna 310
* Beech Baron
* Piper Seneca
sequence=;pre-1962:UO-1

lists=

see also=