Piper Aztec PA-23-250 (F model)

Piper bought the Stinson Twin Stinson design and reworked it into the Apache (PA-23) in 1954. The Apache was Piper's first twin, with two 150 hp Lycoming O-320s and a four-seat cabin. By 1959 Piper had stretched the design, added more powerful 250 hp Lycoming O-540 engines, and renamed the result the Aztec PA-23-250. The Aztec was Piper's entry into the higher-power six-seat twin market against the Beech Travel Air and the Cessna 310 of the same era.

Production tracked through variants A (1960-1961), B (1962-1963), C (1964-1968), D (1969), E (1972-1975), and F (1976-1981). The major design refinements happened in the C model, which adopted the swept tail and refined fuselage. The F model is the final and most refined Aztec, with the IO-540-C4B5 fuel-injected engines and a number of detail improvements over earlier variants. Piper ended Aztec production in 1981 when the company was consolidating its piston-twin lineup around the Seneca.

The Aztec earned a reputation as the truck of the piston-twin world. It was used heavily by air-taxi operators, freight haulers, jump planes, and small flight schools. Many Aztecs in the current used market have substantial commercial-utility hours on the airframe. The flip side is that the airplane has been thoroughly debugged across more than four decades of fleet use. Parts and shop support remain reasonable through Piper Owner Society and the broader independent shop network.

The Aztec cruises at about 175 KTAS at 75% power and 6,000 to 8,000 feet, burning roughly 27 gph total. Long-range cruise at 65% drops to about 160 KTAS on 24 gph total. These numbers are slower than a Baron 58 (200 KTAS at similar settings) or a Cessna 310R (200 KTAS), but the Aztec keeps pace on fuel burn because the airframe is heavier and burns more energy producing the same thrust. The IO-540s loaf at cruise settings, which contributes to the engine's reputation for going past TBO without complaint.

Useful load is the Aztec's quiet advantage over the other piston twins. A typical F model has about 1,800 to 1,900 pounds of useful load. Full fuel (137 gallons usable on most F variants) leaves about 850 pounds for people and bags. That's six adults plus real luggage, which is impossible in a Seneca V or a 310R. The Aztec hauls. Single-engine performance is competitive in the category, with about 240 fpm climb at sea level standard. Range with reserves is about 1,000 nm at long-range cruise.

The Lycoming IO-540-C4B5 (F model) is a six-cylinder, fuel-injected, direct-drive piston engine with a 2,000-hour TBO per Lycoming Service Instruction 1009 BE. It runs on 100LL. Earlier Aztecs used the carbureted O-540-A1B5 with the same TBO. The IO-540 family is one of the most widely-installed engines in general aviation, with the same engine used in Saratogas, Cherokee Sixes, and Maule M-7s. Parts and shop support are universal.

Field overhauls at Gann Aviation, Western Skyways, or other reputable shops run $36,000 to $50,000 per engine in 2026 prices. The IO-540-C4B5 is meaningfully cheaper to overhaul than the IO-520-MB in a Cessna 310R or the IO-550-C in a Baron 58. The lower per-engine overhaul cost is a significant ownership-economics advantage for the Aztec.

Oil consumption on a healthy IO-540-C4B5 runs about 0.4 to 0.6 quarts per hour per engine. Cylinder work at top-overhaul intervals (around 1,200 to 1,500 hours on hard-flown engines) runs $3,000 to $4,500 per cylinder. The IO-540 is not a maintenance-hungry engine when operated and managed reasonably. Many Aztecs in the used market have engines past TBO and still flying with good compressions and acceptable oil consumption.

Plan on $300 to $450 per flight hour at 150 hours a year of utilization, all-in. The Aztec is the cheapest cabin-class twin to own in the category. Fuel and oil run about $140 to $180 per hour at 27 gph and $5.50 to $7 fuel. Engine overhaul reserve is $40 to $55 per hour for two IO-540 engines at $36,000 to $50,000 each over 2,000-hour TBO. Prop reserve is $3 to $5 per hour. Airframe maintenance reserve is $40 to $65 per hour.

Annual fixed costs (hangar, insurance, annual inspection) add another $75 to $120 per hour at 150 hours a year of utilization. Insurance on the Aztec is typically lower than on a Baron or Seneca V because hull values are lower. First-time twin owners can pay $9,000 to $18,000 for first-year coverage. Established Aztec pilots with 300-plus hours in type pay $5,000 to $8,000.

Acquisition cost in mid-2026: A flyable Aztec C or D with mid-time engines and basic panel trades $90,000 to $140,000. An Aztec E with fuel-injected engines and decent panel runs $100,000 to $160,000. An Aztec F with fresh engines and modern Garmin avionics sits at $140,000 to $180,000. The Aztec's quiet advantage is that the per-dollar capability (useful load, range, twin redundancy) is the best in the piston-twin market.

Piper Owner Society is the type-club resource. There's no dedicated Aztec club, but the Piper Apache Club welcomes Aztec owners and the broader Piper community has accumulated decades of Aztec-specific knowledge. The Aztec rewards owners who do their own maintenance or work with shops familiar with the type.