Piper Cherokee
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- :This article refers to Piper's PA-28 series of two- and four-seat aircraft. For the PA-32 six-seat series, see the Piper Cherokee Six article.
Cherokee is the common name for the Piper's PA-28 family of aircraft models, which received its type certificate from the FAA in 1960 and is still under production by The New Piper Aircraft Company.
The Cherokee is an all-metal, unpressurized, four-seat, single-engine piston-powered plane with low wings and tricycle landing gear; its main competitors have been the Cessna 172 and the Beechcraft Musketeer. All Cherokees have a single door on the co-pilot side, which is entered by walking on the wing. The low-end Cherokees are popular trainers.
Piper has created variations on the Cherokee by installing engines ranging from 140 to 235 horsepower (105 to 175 kW), fixed or retractable landing gear, fixed-pitch or constant-speed propellers, and even turbocharging.
History
At the time of the Cherokee's introduction, Piper's primary single-propeller, all-metal aircraft was the Piper PA-24 Comanche, a larger, faster aircraft with retractable landing gear and a constant-speed propeller. Karl Bergey, Fred Weick and John Thorp designed the Cherokee as a less expensive alternative to the Comanche, with lower manufacturing and parts costs (though some later Cherokees also featured retractable gear and a constant-speed propeller), to compete with the Cessna 172. The Cherokee and Comanche lines continued in parallel production serving different market segments for over a decade, until Comanche production was ended in 1972, to be replaced by the Piper PA-32R family.The original Cherokees were the Cherokee 150 and Cherokee 160 (PA-28-150 and PA-28-160), which started production in 1961 (unless otherwise mentioned, the model number always refers to horsepower). The current Warrior model is the descendant of the Cherokee 160. In 1962, Piper added the Cherokee 180 (PA-28-180) powered by a 180 horsepower (134 kW) Lycoming O-360 engine. The extra power made it practical to fly with all four seats filled and the model remains very popular on the used-airplane market. The current Archer model is the descendant of the Cherokee 180. Piper continued to expand the line rapidly: in 1963, the company introduced the even more powerful Cherokee 235 (PA-28-235), which competed favourably with the Cessna 182 for load-carrying capability; in 1964, the company filled in the bottom end of the line with the Cherokee 140 (PA-28-140), which was designed for training and typically shipped with only two seats at first.
One source of confusion is the fact that the PA-28-140 was slightly modified shortly after its introduction to produce 150 horsepower (112 kW), but kept the -140 name. Piper also produced a Cherokee 6 which featured a stretched fuselage and seating for one pilot and five passengers.
In 1967, Piper introduced the PA-28R-180 Cherokee Arrow. This aircraft featured a constant-speed propeller and retractable landing gear and was powered by a 180 horsepower (134 kW) Lycoming O-360 engine. The engine was upgraded to 200 horsepower (149 kW) in 1969 and the designation was changed to PA-28R-200. At the same time as the Arrow was introduced Piper removed the Cherokee 150 and Cherokee 160 from production.
In 1968, the cockpit was modified to replace the "push-pull" style throttle with a more modern style with levers for the throttle and mixture. In addition, a third window was added to each side, giving the fuselage the more modern look seen in current production descendents.
In 1971, Piper released a Cherokee 140 variant called the Cherokee Cruiser 2+2; although the plane kept the 140 designation, it was, in fact, a 150 horsepower plane (112 kW), and shipped mainly as a four-seat version. In 1973, the Cherokee 180 was named the Cherokee Challenger, and had its fuselage lengthened slightly and its wings widened, and the Cherokee 235 was named the Charger with similar airframe modifications. In 1974, Piper fiddled with the names again, renaming the Cruiser 2+2 (140) to simply Cruiser, the Challenger to Archer (PA-28-181), and the Charger (235) to Pathfinder. Piper also reintroduced the Cherokee 150 that year, renaming it the Cherokee Warrior (PA-28-151) and giving it the Archer's stretched body and a new, semitapered wing.
In 1977, Piper stopped producing the Cruiser (140) and Pathfinder (235), but introduced a new 235 horsepower (175 kW) plane, the Dakota (PA-28-236), based on the Cherokee 235, Charger, Pathfinder models but with the new semi-tapered wing. A 200 horsepower (149 kW) Turbo Dakota (PA-28-201T) briefly followed but did not sell well and soon stopped production. In 1978, Piper upgraded the Warrior to 160 horsepower (119 kW) PA-28-161, changing its name to Warrior II.
The PA-28 was also built under licence in Brazil as the Embraer EMB-711 Corisco (PA-28R-200), EMB-711T Corisco Turbo (PA-28R-200T), and the EMB-712 Tupi (PA-28-181).
The original Piper Aircraft company declared bankruptcy in 1991. In 1995, The New Piper Aircraft company was set up. As at 2005 it produces three PA-28 Cherokee variants: the 160 horsepower (119 kW) Warrior III (PA-28-161), the 180 horsepower (134 kW) Archer III (PA-28-181), and the 200 horsepower (149 kW) retractable Arrow (PA-28R-200), which also comes in a turbocharged version (PA-28R-200T). All are now available with Avidyne FlightMax glass cockpits, like many new general aviation aircraft.
Wing design
Originally, all Cherokees had a constant-chord rectangular planform wing popularly called the Hershey Bar wing because of its resemblence to a flat candy bar. Beginning with the Warrior in 1974, Piper switched to using a tapered wing with the NACA 652-415 profile and a two foot longer wingspan.The wing change brought about several notable differences in flying characteristics.
The fundamental difference between the two wings from an aerodynamic perspective is that the "Hershey Wing" produces substantially more Induced Drag, while the longer span and non-Laminar airfoil on the tapered wing tends to produce higher Profile Drag. This difference manifests itself in the fact that the Tapered wing is a substantially better gliding platform than the "Hershey Wing".
The Tapered Wing's glide ratio is substantially better, giving it more time and range to find an airport in an emergency, the wing also suffers greatly from 'ground effect' in landing configuration, necessitating very careful control over touchdown speed. The "Hershey Wing" on the other hand requires higher speeds in the traffic pattern, but will tend to settle much more smoothly and easily on the ground on touchdown. The "Hershey Wing" also suffers from a substantially smaller Stabilator with less Authority for flare, increasing the risk of an improper 'wheelbarrow' on landing. Also, being a more conventional airfoil, the Hershey Wing's stalls are very 'conventional' breaks that are among the most benign and controllable of any general aviation aircraft.
The "Hershy Wing" is not without its advantages, however. The thick chord, laminar flow airfoil, combined with the shorter wingspan provide a 'roll control balance' that many pilots consider for superior than the Tapered wing. Furthermore, there is far more performance potential in the "Hershey wing". A cottage industry has built up around speed improvements for the "Hershey Wing", optimizing the laminar flow and reducing the Induced Drag. These inexpensive and simple improvements provide much greater benefit to the older wings. Furthermore, many pilots advocate that the tendency of the "Hershey Wing" to 'mush' into a stall instead of 'break cleanly' is actually a safety benefit for the average pilot, and indeed, the older "Hershey Wing" aircraft have a notably lower record of in-the-pattern stall-spin accidents which would tend to back up this assertion.
As might be expected, the two Cherokee wing designs are the source of a great deal of debate inside the Cherokee community. Although, like the low-wing vs high-wing general aviation debate, the general consensus is that the 'correct' answer is merely a matter of pilot preference.
Flight Controls and Flaps
For the Cherokee family Piper used their traditional flight control configuration. The horizontal tail is a stabilator with an anti-servo tab. The anti-servo tab moves in the same direction of the stabilator movement, making pitch control "heavier" as the stabilator moves out of the trimmed position. The flaps are manually actuated using a lever located between the front seats. For zero degrees flap the lever is flat against the floor and is pulled up to select flaps to the detent positions of 10º, 25º and 40º.Specifications (PA-28-161 Warrior II, 1982- )
Where a single speed appears, it is applicable to the aircraft at maximum gross weight (2440 lb/1107kg). Where a range appears, the lower speed is applicable at empty weight (1531 lb/694 kg) and the higher speed is applicable at maximum gross weight.
- Vr (no flaps, rotation): 45-55 kias (83-102 km/h)
- Vr (25 ° flaps, rotation): 40-52 kias (74-96 km/h)
- Vx (no flaps, best angle of climb): 63 kias (117 km/h)
- Vx (25° flaps, best angle of climb): 44-57 kias (82-106 km/h)
- Vy (best rate of climb): 79 kias (146 km/h)
- Va (maneuvering): 88-111 kias (163-206 km/h)
- Vno (max cruise): 126 kias (233 km/h)
- Vne (never exceed): 160 kias (296 km/h)
- Vfe (flaps extended): 103 kias (191 km/h)
- Vref (no flaps, approach): 70 kias (130 km/h)
- Vref (40° flaps, approach): 63 kias (117 km/h)
- Vs (stall, clean): 50 kias (93 km/h)
- Vso (stall, dirty): 44 kias (82 km/h)
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