October 2004 –
If you tell someone you fly a Piper PA-28, you should be a little more specific. There is a choice of 12 separate types with a dozen different names and at least 30 variations on those themes. And they have straight wings or tapered wings and T-tails and flying tails. They range from 113-knot two-seaters to 175-kt cross-country speedsters.
PA-28s comprise the largest number of aircraft Piper has produced over the last 40 years. It all started innocently in the early 1950s, when Piper Aircraft Co. saw the need to supplement—if not replace—their tube and fabric aircraft.
They had been successful with the PA-22 Tri-Pacer, of which they had built nearly 4,500 from 1950 to 1956, but chief competitor Cessna was beginning to corner a big share of the single-engine market with their all-metal 180 (at twice the price) and was making plans to add more models to their line, while Beech’s successful Bonanza was defining GA aircraft of the future.
The company first looked to existing models or freelance designers for inspiration. In 1952 Bill Piper flew to Wichita and made a face-to-face offer to Al Mooney for his new M-20. Turns out that Mooney was more interested in building it himself (or likely, Piper’s offer was too low).
Undaunted, Bill also expressed interest in John Thorpe’s Sky Scooter and also Fred Weick’s Ercoupe design, but finally concluded that any new Piper model would have to be drawn on a clean sheet of paper.
The PA-24 Comanche was Piper’s first departure from its tube-and-fabric designs. There is very little reference to who did the math and laid out the lines, but its un-Piperlike sophistication and complexity leads to the conclusion that it likely was a purchased design.
The Comanche first flew in summer 1956 and entered the market two years later. It was everything previous Pipers were not—modern, all-metal, sleek and fast—and it was in direct competition with the Beech V-35J Bonanza—for a whole lot less money.
Enter the Cherokee. The Comanche was a critical success, but building it while trying to make it lucrative was an accountant’s nightmare. So in 1957, the company decided that if it was going to prosper, it had better get back to concentrating on the low-cost market that had made Piper successful—and profitable.
In January, work started on the preliminary design for a low-cost single, and not coincidentally, three months later Fred Weick was hired to head the project, and he brought John Thorpe along.
Weick, whose Ercoupe originated in the mid-1930s, had been formerly associated with Texas A&M. In 1950 he had headed the effort that designed and built the University’s AG-1, the world’s first dedicated agricultural airplane and a few years later, progenitor of the PA-25 Pawnee.
Overall, the new design was far less complex than the PA-24. Weick specified a basic, easy to build constant chord wing and the “flying tail” stabilator that had premiered on the Comanche. The airplane would be built at the company’s new plant in Vero Beach, Fla., and it had half the number of parts as the Comanche—and 25 percent less than even the simple Tri-Pacer.
The project was assigned status as PA-28 in Piper’s system (#26 was a planned higher-power Comanche and #27 a re-engined Aztec), and the first experimental Cherokee with 150 hp O-320-A2A engine flew on Jan. 10, 1960 in Florida.
The engineering prototype (#28-03, N2800W) was fitted with a 160 hp O-320-D2A. It gained FAA certification on Halloween 1960 and deliveries began early in 1961 as 1962 models.
The four-place Cherokees 150 and 160 were introduced at just over $10,000 with, respectively, 150 hp Lycoming O-320-A2B and 160 hp O-320-B2B engines. They were available with four levels of equipment: Standard, Custom, Super Custom or Auto-Flite. With gross weights of 2,150 and 2,200 lbs, the 150 and 160 were spirited performers, able to get off the ground in 800 feet or less and cruise at 133+ mph, and an enthusiastic public bought 670 units the first year.
When Piper began to promote pilot training with its $5 flight coupons in 1963-64, it backed the program with the $9,000 Cherokee 140, a 1,950-lb. two-seat PA-28 with the O-320-E2B engine de-rated to 140 hp. Two years later the PA-28-140 returned to 150 hp, upped its gross weight to 2,150 lb. and improved both its performance and its sales record. This began a process of stretching, shrinking, expanding, cleaning up and improving the basic design so much that many people refer to these Pipers as the “Cherokee tribe.”
The original Cherokee line (if not its design) was expanded in 1965 with the introduction of the PA-32 Cherokee Six. With seating for six and a gross weight of 3,400 lb., it was originally powered by a 260 hp O-540 Lycoming. But by its second year, it was also available with a fuel-injected 300 hp engine, and was one of perhaps two aircraft on the General Aviation market whose useful load was nearly equal to its empty weight.
Despite a zealous effort to hold prices, Piper took an inordinate amount of time to learn what other designers and manufacturers already knew—that, given a choice, not that many customers opt for lower-power airplanes.
The Hershey Bar wing Early PA-28s used Weick’s constant-chord wing design. It was extremely simple and economical to build, since ribs and some other internal components were standardized. However, normal wing stresses combined with loads from the wing-mounted main landing gear dictated the use of a hefty spar assembly.
The resulting structure was thicker than customers were used to seeing on the old high-wing Pipers or the later Comanches, and its plain rectangular plan form inspired the descriptive “Hershey Bar Wing” moniker. While the square wing may have furnished certain manufacturing economies, its thick airfoil was sometimes perceived by the market as a technical and visual throwback that added no value for the customer.
Design on a new wing began early in 1972, and its first proving flight was on the prototype PA-28-151 Warrior in October of that year. A constant-chord wing distributes flight loads evenly across its entire span, whereas a tapered design that decreases the chord and/or thickness of a wing toward the tip encourages those loads to dissipate at the point of least resistance, the wingtip. And, while it requires additional manufacturing time, it is normally more lightweight because particular loads can be absorbed by different parts of the structure.
The Piper wing was semi-tapered, with both leading and trailing edges tapering outboard from the panels outside the ailerons (which were larger than on previous models). The horizontal stabilator was also widened nearly 12 inches. The combination of expanding these two components improved low-speed and crosswind landing control.
The retractable Cherokee—the 148-kt PA-28R-180 Arrow—debuted in 1967, and featured a unique automatic gear extension system that would lower the gear below a certain airspeed as a reminder to a forgetful pilot. With its speed and passenger comfort, the Arrow became a best-seller.
In 1975, model numbers had a “1” added to their digital titles to differentiate between the old “Hershey Bar” wing and the new wing on the Archer II, Arrow II and later on Dakota and Saratoga models.
During its 40-year lifetime, the basic PA-28 design underwent an extraordinary expansion—cruising speed upped by 60 percent and gross weight by nearly 40 percent. And while a seemingly endless litany of names have been applied to Piper’s popular Cherokee, it has remained the world’s most popular low-wing airplane—twelve separate types, a dozen different names, 30 variations on those themes.
