Country of origin:

United States of America

Description:

Twin-engine light transport

Power Plant:

Two 186 kw (250 hp) Lycoming O-540-C4B5 six-cylinder horizontally-opposed air-cooled engines

Specifications:

History:

Developed from the Piper PA-23 Apache, and using many common components, the prototype of the Aztec series was flown for the first time in 1959.  Deliveries of the five-seat aircraft began in 1960, and one of the first customers was the US Navy, which obtained the type as the U-11A for communications duties.

Compared to the Apache, the Aztec had a re-designed fuselage which had been lengthened to provide additional passenger accommodation. The wings and many other components remained the same but the 112 kw (160 hp) Lycoming O-320B engines were replaced by 186 kw (250 hp) Lycoming O-540s six-cylinder engines, thus permitting an increase in all-up weight by 454 kg (1,000 lb) to 2,177 kg (4,800 lb).

In 1962 the Aztec B was introduced with a new elongated nose housing a second luggage compartment, a modified instrument panel, improved maintenance accessibility, and an extra seat.  Subsequently the Aztec C appeared, this being fitted with similar engines to the B model but with fuel injection, and had an increase in all-up weight to 2,358 kg (5,200 lb).  New features included re-designed engine nacelles, which was made possible by the introduction of extended propeller shafts on the engines, new undercarriage doors, which closed completely when the undercarriage was retracted, cowl flaps, new light-weight Hartzell propellers, and improved sound-proofing. Total luggage capacity was 136 kg (300 lb), and fuel capacity was 545 litres (120 Imp gals).

Variants of the Aztec C had turbocharged fuel injected IO-540-C4B5 engines, and six seats, whilst the Aztec D introduced in 1969 had IO-540-J4A5 engines.  The Aztec E released in 1970 had a 30.4 cm (12 in) longer nose for more baggage and / or weather radar, and the nose baggage compartment load was increased to 68 kw (150 lb). The Aztec F was introduced in 1976 and had a re-designed stabilator, the wingtips being rectangular rather than semi-elliptical. Corresponding turbocharged variants introduced detail changes. The F model had long-range fuel tanks as an option, thus increasing the capacity by 151 litres (33 Imp gals). Fuel was contained in four tanks in the wings.

Aztecs were available with a range of equipment, from the basic model through to corporate and international levels. Production of the series concluded in 1982. The most numerous model was the Aztec C with 1,435 delivered. Piper in 1970 advertised the Aztec D as “All over the world, the Piper Aztec D offers pilots the advantages of high speed…safe, easy operations out of short, rough airfields…functional, professional instrument panel , and airline-type comfort…excellent stability under every type of flying condition. Also on a production schedule of two per day, it takes twenty-two days to complete each twin engined Piper Aztec.”

Construction was steel tube frame with sheet metal panels.  The wings had a main spar in each wing bolted together to create a single continuous spar, and front and rear spars of constant chord.  The nose contained the retractable nosewheel, plus luggage space, models E and F having a more pointed nose.

In the order of 100 Aztecs have been registered in this region over the years, and most have been used on charter and light freight work. A few were flown by TAA (later Australian Airlines) in northern Queensland in the early 1960s, and the Avis Rent-A-Car Company, trading as Avis Rent-A-Plane, had at least 17 Aztecs in its fleet for hire between 1961 and 1971 (nearly all registered in the VH-AVA to VH-AVZ block). One of this Company’s aircraft, an Aztec 250B VH-AVR (c/n 27-2192 – ex VH-PKR, VH-FRM), was fitted with a magnetometer in the tail, survey gear, radio surveillance, photographic equipment and geological equipment for mineral survey work in the Solomon Islands on behalf of the United Nations. This aircraft was later exported to New Guinea in May 1974 as P2-AVR.

Some 50 survive in Australia and 14 in New Zealand.  Others have been used by commuter airlines. Production of the Aztec ceased in 1982 after 4,929 examples had been completed. A number have been fitted with floats in the USA and Canada.