Piper PA-24 Comanche

PA-24 Comanche

PA-24-250
Role	Civil utility aircraft
Manufacturer	Piper Aircraft
Designed by	Howard "Pug" Piper
First flight	May 1956
Introduced	1957
Status	production ceased
Primary users	Private aviators Flight schools
Produced	1957-1972
Number built	4,857
Unit cost	$17,850-$36,890
Variants	Piper PA-30 Twin Comanche Piper PA-39 Twin Comanche

The Piper PA-24 Comanche is a four-seat, low-wing, all-metal, light aircraft of monocoque construction with retractable landing gear that was first flown in May 1956 according to a Piper Aircraft Company press release. Together with the Twin Comanche, it made up the core of the Piper Aircraft line-up until 1972, when the production lines for both aircraft were wiped out in a flood.

Production history

Development

It is reported that Pug Piper made many of his design choices based on existing aircraft. The laminar flow wing was a feature found on the P-51 Mustang fighter. The Comanche's swept tail was evocative of 1950s fighter aircraft, and the stabilator was a prominent feature of the Bell X-1, the first aircraft to break the sound barrier.

Comanche 180

The original version of the Comanche was the PA-24, which featured a carbureted 180 hp (134 kW) Lycoming O-360-A1A engine, swept tail, laminar flow airfoil, and all-flying stabilator. Designed by Howard "Pug" Piper, the new Comanche was intended to compete in the market with the very successful Beechcraft Bonanza.

The initial production run of the 180 hp (130 kW) Comanche singles were given the PA-24 type designation. The remainder of this production run were given the PA24-180 designation.

The standard fuel capacity of the PA-24-180 was 60 gallons. The flaps were manually actuated, controlled by the same Johnson bar actuator as the Piper Cherokee. The aircraft specifications were for cruise speeds of 116 to 139 knots (257 km/h) and fuel burns between 7.5 and 10.5 gph at 55-percent and 75-percent power settings. Full-fuel payload with standard fuel was 715 pounds, with a gross weight of 2,550 lb (1,160 kg) and range with 45-minute reserve of 700 nautical miles.

When new, standard, average-equipped Comanche 180s sold between $17,850 (1958) and $21,580 (1964). A total of 1,143 were built.

Comanche 250

In 1958 Piper introduced a 250 horsepower (186 kW) version using a Lycoming O-540 engine, giving the PA-24-250 Comanche a top cruise speed of 160 kts (185 mph; 298 km/h). Most 250s had carbureted Lycoming O-540-AIA5 engines, but a small number were fitted out with fuel-injected versions of the same engine. Early Comanche 250s had manually-operated flaps and carried 60 gallons of fuel. Auxiliary fuel tanks (90 gallons total) became available in 1961. Electrically actuated flaps were made standard with the 1962 model year. The aircraft's gross weight was increased from 2,800 pounds to 2,900 pounds in 1961, making the useful load 1,270 pounds.

The Comanche 250 advertised cruise speeds of 140-157 knots and fuel burns of 10-14 gph (55% and 75% power).

Prices of new Comanche 250s ranged from $21,250 (1958) to $26,900. Which was only $3,000 to $5,000 more expensive than the Comanche 180. Some 2,537 were sold.

Comanche 260

In 1965 the first of four 260 horsepower (194 kW) versions of the Comanche was introduced. They were:

A total of 1,029 airplanes were sold from the Comanche 260 line, including the 260TC. 38 Comanche 260s were delivered with carbureted engines; the rest used the fuel-injected Lycoming IO-540 engine.

The 260 had an empty weight of approximately 1,700 pounds and a max gross weight of 2,900 pounds. It had four seats and a 90-gallon-capacity auxiliary fuel system was available as an option. Cruise speed was advertised as 142-161 knots with fuel burn of 10-14 gallons per hour. New, they sold for approximately $30,740.

The 260B had an overall length six inches (152 mm) more than the previous models. This was due to a longer prop spinner, not a longer fuselage. The 260B had a third side window and a provision for six seats. The fifth and sixth seats are suitable only for children and take up the entire baggage compartment. Typical empty weight was 1728 pounds and gross weight was 3,100 pounds. Fuel burn was 11-14 gallons per hour and advertised speed was 140-160 knots. New, they sold for $32,820 to $33,820.

The 260C introduced a new "Tiger Shark" cowling, max gross weight of 3200 pounds, cowl flaps, and an aileron-rudder interconnect. Cruise speed was advertised as 150-161 knots with fuel flow of 12.5-14.1 gallons per hour. To prevent possible aft center of gravity problems due to the increased gross weight and its fifth and sixth seats, the propeller shaft was extended. This moved the center of gravity slightly forward. With a useful load of 1427 pounds it has the largest payload of all of the Comanches except the 400. Often mistaken on the ramp for the 400 model, the slightly longer cowling includes a distinctively longer nose gear door, as compared to the B models and older versions. New, they sold for $36,550 to $45,990.

Comanche 260TC (turbo)

The 260-TC (1970 to 1972) had a turbo normalizing system of dual manually controlled Rajay turbochargers. These were controlled by what Piper called a "second throttle" on the power quadrant. This manually controlled turbocharger was used by first using throttle to bring manifold pressure up to the desired level. If conditions are such that insufficient manifold pressure is developed for the task at hand, then the pilot would begin closing the turbo's wastegate by moving the turbocharger lever forward.

Comanche 400

The PA-24-400 Comanche 400, while identical in planform to other single-engined Comanches, is structurally strengthened, primarily in the tail. The aircraft has an extra nose rib in the stabilator and in the vertical fin. The stabilator, vertical fin, and rudder of the 400 share virtually no common parts with the 180, 250, and 260 hp (190 kW) Comanches. In addition, the 400's rudder is aerodynamically balanced in a manner similar to that of the Piper PA-30 Twin Comanche and does not have the lead external balance weights of the lower-powered single-engine Comanches.

The Comanche 400 is powered by the 400 horsepower 8-cylinder Lycoming IO-720 engine, an engine developed specifically for the Comanche.

Only 148 PA-24-400s were built. The aircraft's high fuel burn means that it is expensive to operate and there have been cooling problems with the rear cylinders of the horizontally-opposed eight cylinder engine. Even with the huge engine the PA-24-400 only manages a top speed of 194 knots (360km/h) and cruising speed of 185 knots (343km/h), considerably slower than more modern light aircraft, like the Cessna 400, operating with much less horsepower.

The Comanche 400 has a three-blade propeller and carries 100 gallons of fuel, or 130 gallons with optional extended tanks. Fuel burn was advertised as 16-23 gallons per hour, at 55%-75% power. The 400 had a typical empty weight of 2,110 pounds and a max gross weight of 3,600 pounds. New base price for 1964 was $28,750 according to PIPER AIRCRAFT by Roger W. Peperell.

Twin Comanches

PA-33

In 1967 a single Comanche was modified by Edward Swearingen to pressurize the cabin. The prototype was designated the PA-33, but Piper decided not to put the aircraft into production. The one prototype PA-33 was scrapped following a taxiing accident. The exterior design of the PA-33 was later used as a basis for the Piper Malibu.

End of production

Production of the Comanche ended in 1972 when torrential rains from Hurricane Agnes caused the great Susquehanna River flood of 1972, flooding the manufacturing plant and destroying airframes, parts, and much of the tooling necessary for production. Rather than re-build the tooling, Piper chose to abandon production of the Comanche and Twin Comanche, and continue with two newer designs already in production at Piper's other plant in Vero Beach, Florida: the twin engine PA-34 Seneca and the PA-28R-200 Arrow.

At that time Piper had already begun to concentrate on its successful Piper PA-28 Cherokee line, which had originally been conceived as a cheaper alternative to the Comanche. The Arrow was a retractable gear version of the popular Cherokee trainer; its smaller 200 horsepower (150 kW) engine was less expensive and easier to fly than the Comanche; sales of the single engine Comanche had faltered after the introduction of the Arrow in 1967.

The Comanche production run ended with the disposal of all of the tooling, and completion of the last seven airframes. After the Susquehanna River receded, Piper moved the last aircraft to Vero Beach and completed construction there. The self-described junior member of the completion team was Chuck Suma, who 30 years later would become the CEO of The New Piper Aircraft, Inc.

Fuel capacity and modifications

Factory-installed auxiliary fuel tanks in the wings gave the Comanche a fuel capacity of 90 US gallons (341 litres) and a range of nearly 1,125 miles (1,800 km) for some models. Later modifications include a wingtip fuel tank modification that gave the Comanche an extra 30 US gallons (113 litres) of fuel. Some Comanche aircraft have all six tanks installed, giving a fuel load of 120 gallons.

Airframe modifications include a host of aerodynamic refinements. The most commonly applied modification in the fleet is the single windshield conversion, which modernizes the appearance of the aircraft. Wing modifications include wing root fairing, gap seals, upswept wingtips and the 'gear lobe' fairing, which adds a fiberglass globe behind the exposed main wheel in the retracted position.

The most important speed mods available actually were Piper factory improvements. During the mid-60's, reports of flutter issues led Piper to issue a kit to add balance weights to the rudder. By the mid 70's, they added a kit to put weights on the ends of the stabilator. Addition of both kits raises V_ne (never exceed speed) from 207 to 227 mph (365 km/h).

World Record

In June 1959 Max Conrad flew a Comanche 250 on a record-breaking flight. Having removed the interior seats and replaced them with fuel tanks, Conrad flew non-stop from Casablanca, Morocco to Los Angeles, a distance of 7,668 statute miles (12,340 km). When the aircraft took off from Casablanca, it was loaded 2,000 pounds (910 kg) over its production gross weight limit.

Today

The aircraft's aircraft type club, The International Comanche Society, hosts fly-ins, prints a monthly magazine and offers training specific to the model.