Cub Clones

Cub Clones

By Budd Davisson, EAA 22483

This piece originally ran in the July 2021 issue of EAA Sport Aviation magazine.

One of the strongest indications that a product has a fanatical following is when tens of thousands were built in the first place, many of which still exist, yet there’s a sizable industry aimed at building replicas. Clones, as it were. That’s the way it is with all the variants of Piper Cubs. They’re still super common, yet it is so loved that there’s a market for new ones — especially experimental amateur-built (E-AB) versions that can be molded to fit an individual’s specific tastes and needs.

Approximately 20,000 J-3 Cubs and variants were originally built (1938-1947), and then another 15,000 PA-18 Super Cubs (1949-1983, 1988-1994). Since then, it is hard to imagine how many have been built as certified utility category aircraft by CubCrafters; how many light-sport aircraft by Legend Cub; and how many homebuilt look-alikes-but-not-really (most are modified) have come via the DIY route from numerous kits and plans. There is no accurate adjective that adequately describes the phenomenon that is the Piper Cub. Trying to write about the Cub is like trying to describe dirt: It’s so basic everyone knows everything there is worth knowing about it. Still, as we look at the new generations of Cubs that are being born, it’s worth looking back just far enough to see how the Cub became the Cub in the first place.

In the Beginning

In reality, there were five distinctly different Cubs. Six, if you want to go back to the beginning in the late 1920s. The first Cub version, which Cuboholics might disavow as not really being a Cub, is the Taylor/Arrowing Chummy, which C.G. Taylor and his brother Gordon designed and built in 1928. It was a trim, slender fuselage with a two-place, side-by-side open cockpit and a wing suspended over it, parasol-style.

The Chummy led to a nearly identical airplane, the Taylor E-2 Cub of 1931. It still had the pilot and passenger outdoors, but the seating was tandem rather than side by side. The majority were powered by the flathead four-cylinder Continental A40 that, on a good day, put out 37 horses. They tried a wide variety of power sources but the A40, although underpowered, turned out to be the logical engine.

In 1935, by which time the E-2 was looking dated, the Cub took a turn for the better. If some sources are to be believed, C.G. Taylor was sick for a short time. When he returned to work, one of his employees, engineer/designer Walter Jamouneau, had redesigned the airplane considerably. All of the squarish outlines on the wings and tail were gone, replaced by pleasingly curved ones, and the rear, upper fuselage line flowed up to the back of the wing, essentially eliminating the open cockpit. At that point, the airplane became recognizable as the Piper Cub loved by so many today.

Reportedly, Taylor was so incensed that Jamouneau dared to make such design changes in his absence that he fired him. A few months later, oilman Bill Piper took over management of the financially troubled company, buying Taylor out in the process. Taylor was barely out of the door before Piper rehired Jamouneau and put him to work on a drafting board where he stayed for the rest of his working life. Out of that relationship, further changes were made to the J-2, and it became the J-3 icon we all know today.

The J-3 was, and still is, an outstanding airplane. However, it has to be recognized that if the 65-hp Continental O-170, also known as the A65, hadn’t been invented, the lightplane industry as we know it today wouldn’t have tasted the success it did, when it did. By 1940 almost the entire two-place light aircraft market was powered (note the “almost”) by the Continental engine. Lycoming’s O-145 grabbed a part of the market but was largely unsuccessful. Ditto for the Franklin O-170/175.

The J-3 was produced through World War II as an L-4 Grasshopper and continued in production after the war. Its wooden spars were eventually replaced with aluminum before production ended in 1947. In 1938, the J-3 was joined by the J-4, a relatively little-known version of the J-3 (only 1,250 were built). It’s the same airplane but, probably in response to Taylorcraft’s new aircraft, the J-4 had side-by-side seating rather than tandem. For the same reason, competing with Taylor, later versions of the J-4 had a streamlined cowling that enclosed the entire engine. It was produced 1938-1942.

The J-3 was replaced by the PA-11 Cub Special in 1947 (postwar, Piper dropped the “J” designation and went to “PA,” Piper Aircraft, numbers). The warmed-over J-3 featured the streamlined cowling introduced on the J-4A, the seats were moved back slightly, and the airplane was soloed from the front seat rather than the back. For many, the PA-11 is the ultimate J-3, but the progression of changes led to what may be the ultimate son-of-a-Cub, the PA-18 Super Cub. The Super Cub has become a standalone icon in its own right and has given rise to a mini industry of clones, modifications, DIY experimentals, and a multitude of parts manufacturers.

The Super Cub took the basics established by the PA-11 Cub Special — enclosed engine, lightweight, rag and tube construction, and simplicity — and then added flaps, widened the fuselage, and moved the wing attach points to the outside of the fuselage rather than over the pilot’s head. More importantly, after the first few flapless 95-hp PA-18-95 versions, a 150-hp O-320 Lycoming was hung ahead of the firewall. That’s where the “super” in the name came from.

The Cub Today

Here’s a flat statement that’s difficult to dispute: The Cub has spawned more support and modification companies than almost any other single-engine airplane. These companies make new PMA parts, manufacture lots of duplicate or modified complete airframes in the experimental category, have produced a ton of STCs that correct built-in design deficiencies, and are building and certifying both modified and stock FAA type-certificated updated versions of the original. Essentially, the Cub concept is a seed that, once it was planted, bloomed in an unbelievable number of different directions.

If a backyard builder wants to build a highly modified Super Cub clone that lets him drop into minuscule semi-flat stretches of wilderness, it’s available. Or, if a pilot just wants to enjoy her autumn evenings in something that exactly replicates a J-3 that came out of Lock Haven in 1939, that’s available, too. There are lots of companies out there that can give pilots exactly what they want.

A Homebuilding Service: Scratchbuilding Meets LEGO

As an aside, a company that doesn’t actually build anything but provides an amazing service to Cub builders, and homebuilders in general, is VR3 Engineering. It has offered pre-cut steel kits for a wide range of rag and tube designs for decades, including the stock PA-18 Super Cub and a wide-body version that is 3 inches wider, a common Super Cub modification.

VR3 CNC cuts every single piece of tubing for every part of the airplane, carving each end so it exactly fits to the next member and is ready to be welded. Everything clicks together. Where a curved tubing member is required, as for the leading and trailing edges of stabilizers or vertical fins/rudders, that tubing is bent by computer, and all the adjoining pieces fit the curve with computer accuracy. This takes an enormous amount of time out of the build cycle and reduces the required jigging and the acquisition of the right sizes and lengths of steel almost to nothing. If requested, VR3 can also do the welding.

Improving the Breed

It is worth noting that none of the Cub companies we’re about to mention build a Super Cub that is as exactly as it was when it came out of the factory for the last time in 1994. Even before the PA-18 went out of production, there was a narrow niche industry that manufactured STC’d modifications and improvements for the airplane. Companies like F. Atlee Dodge have been focused on improving the myriad of small details that, over the Super Cub’s service life, had proved to be less than perfect. This could be expected because, at the time of the airplane’s birth, the Piper engineers couldn’t have imagined how dramatic their little airplane’s life would be in the future. STCs have corrected those shortcomings.

When the Super Cub was designed in the late 1940s, Piper was still trying to survive the intense depression that had descended upon general aviation as the result of the much-anticipated returning-GIs-boom that didn’t happen. As a survival tactic, Piper began introducing new designs on an almost yearly basis to attract new customers. However, Piper management wisely dictated that the product line expansion had to be done as inexpensively as possible. That meant every new design used materials that it already had on hand and parts it was already tooled to build. Everything from mag switches to entire tail groups was reused in follow-on designs where possible. So, the Super Cub offered nothing even remotely new technologically but combined older, proven concepts and parts with a few new ideas for a new purpose.

In 1947, while the PA-18 was on the drawing board, no public road connected Alaska to the lower 48 United States. The Alcan highway, which was completed in 1942, was intended for military use only and opened to the general public in 1948. For that reason, Alaska, and bush flying in general, only existed on the outer fringes of the Piper engineers’ imaginations. The company saw the immediate market for its new design as farmers/ranchers, sportsman pilots, flight instructing, glider towing, and crop spraying. The concept of bush flying, as either entertainment or on-demand adventure, was in its infancy. No one in the engineering department envisioned the new design skimming its tires on a river surface and finishing the landing roll on a sandbar or carrying lumber under its belly or on the struts while wearing incredibly big shoes. They couldn’t have imagined how crude landing conditions would get.

The stock Super Cub opened up many new adventures to pilots, which subjected it to conditions far outside of its original design envelop so things started breaking. And those who were using the airplane came up with fixes that were eventually STC’d. Then the airplane went out of production. The result was that various aerial entrepreneurs responded to fill the void. Many new, and not so new, designs, evolved to serve the market, type-certificated and otherwise.

The DIY J-3

If originality is what the homebuilder wants in a Cub, Wag-Aero in Lyons, Wisconsin, has offered its Sport Trainer to the sport aviation market for decades. Its J-3 style kits are a combination of raw materials (uncut lengths of the right diameter and wall thickness of tubing) that must be trimmed to fit, while all of the tabs and gizmos that will be attached to the fuselage frame are pre-cut and pre-formed. So, the builder cuts and fits the tubing, jigs it, and welds it together. However, Wag-Aero does make pre-welded landing gears and tails.

The wing’s aluminum ribs use the original J-3 type of “T” section material for its pre-build ribs, and the spars are aluminum extrusions available through Wag-Aero. It also offers the wings in the shorter “Clipped Cub” configuration for those who want a super fun, easy-to-fly aerobatic bird. They are stressed for up to 115 hp, but obviously, since the airframe is being scratchbuilt by the pilot, the builder can make the appropriate changes so it can handle more horsepower if desired. In addition to the homebuilt parts that yield a modern J-3, Wag-Aero also produces a wide range of certified PMA parts for Cubs and others in its peer group.

Wag-Aero is the primary producer of J-3 kits, but updated Cubs and Super Cubs are available in different configurations from several suppliers. This includes some that are certified and ready to fly and some that arrive in huge crates, with no welding required.

Ready-to-Fly or a Kit?

Today, those wanting a Super or J-3 Cub who aren’t builders have several choices. The two most obvious are CubCrafters and Legend Cub. What makes them interesting is that both produce certified ready-to-fly Cub variants and kits.

Legend Cub has two LSA-compliant, ready-to-fly aircraft that are also available as kits and a total of around six variations, 100 hp to 195 hp. It tends to specialize in aircraft that are closer to the J-3/PA-11 mold than the Super Cub, but all of them are wider than the originals, fly from the front seat, etc. All are improvements on the basic J-3 theme. That said, its MOAC (Mother of All Cubs) E-AB kit is a 195-hp, highly modified airframe with lots of flap that takes a direct shot at the modified PA-18 crowd. That one is available only as an E-AB kit.

CubCrafters, on the other hand, is Super Cub specific. It started out nearly 35 years ago repairing and modifying Super Cubs. However, it quickly launched the production of its own FAR Part 23 certified Super Cub aircraft that it now labels as its XCub. It then branched out into its phenomenally successful LSA-certified Carbon Cub, which means it is a full-production ready-to-fly airplane. Further, CubCrafters has developed a proprietary 186-hp engine driving a constant-speed prop that gives tremendous performance while still complying with LSA regulations. And, dare we say it, it even has a nosewheel version.

The Carbon Cub kits are also available as E-ABs with a builder-assist program attached, or it can show up on your front step in a gigantic box as a straight E-AB kit. Its FAA-approved builder-assist program breaks the airplane down to the exact type and number of tasks the builder must do to qualify for the 51 percent (or majority) requirement of the E-AB category. Builders physically travel to the factory, where they take delivery of their kits. They spend a week or so completing a number of the required tasks and then come back again later for several days to complete the list of tasks. At that point, a designated airworthiness representative issues the airworthiness certificate and the builder has a completed airplane. The factory does the first test flights, and the builder flies off the remaining test time within 75 miles of Yakima, Washington. In this particular market, it is the 800-pound gorilla.

In addition to those already mentioned, several other companies are deadly serious about giving builders and pilots a Super Cub that redefines the word “super.” Some are highly developed PA-18 based designs while others are, for all intents and purposes, new designs that use the Super Cub only as a source of inspiration. The list that follows is in no particular order. If we’ve missed a company, we apologize.

Backcountry Super Cubs

Backcountry Super Cubs, based in Douglas, Wyoming, continually refers to the Super Cub in its marketing materials. However, it has modified the design in so many ways that it could be considered its own design. The familiar wings have slots with slotted Fowler flaps as an option. These result in an advertised flaps-down stall speed of 18 mph (that’s not a typo, 18 mph!) or a 26 mph stall with no flaps. This gives takeoff distances of 47 feet and landing distances under 30 (amount of wind not specified). The kit fuselage comes completely welded, bare 4130 (powder coating in a choice of colors is an option), and a right or left door can be selected. The ailerons and flaps are completely assembled (fabric-covered aluminum structure), and the wings require the builder to assemble them presumably as part of the 51 percent kit approval. The tail structure is ready for cover. There are three different landing gear options including the TK1 Extreme Shock system, the Alpha Omega suspension system, and the Porter style gear. All are designed for serious rough fieldwork. Paint and all covering materials are included in the kit. Backcountry Super Cubs also has a super-wide, super-duper Cub, the BOSS, which is a four-place version.

Dakota Cubs

For more than 25 years Dakota Cub Aircraft of Valley Springs, South Dakota, has been manufacturing and distributing direct-replacement parts for all fabric-covered Piper aircraft, eventually expanding to PMA’d full wing assemblies. It also holds the STCs for a number of Cub-oriented modifications included extended and slotted wings as used on the type-certified Super 18 Model S18-180 Cub clone that’s built by Super 18 LLC, which is not officially affiliated with Dakota Cub. However, Dakota does manufacture the Super 18 in three different versions as 51 percent approved kits. They are available as 180 hp, 160 hp, and 115 hp (LSA compliant). Given its longtime involvement in improving the breed and building type-certificated replacement parts, it’s hardly a stretch for Dakota Cub Aircraft to get into the kit market.

Javron Aviation

Located in Brainerd, Minnesota, Javron specifies that it builds its Super Cub clones to factory drawings. However, recognizing that a factory-stock Super Cub leaves something to be desired in the bush environment, it lists a number of popular modifications that are part of its kits. This includes everything from widening the fuselage 4 inches to a long list of Alaska-oriented modifications that almost all Super Cub owners/operators can’t live without. Recognizing that everyone has their own ideas of what makes a Super Cub super, Javron makes a point of saying, “We can build a kit to your specifications, from original ‘factory’ or the most tricked-out Alaskan machine.” So, it’s a “We make it your way” style of production.

North Star – Custom Flight Ltd.

Custom Flight describes its operation as “low production, high quality.” Meaning, it is not building 100 airplanes a year but supplying a narrow customer base that has specific requirements and tastes. Its airplane, the North Star, is another that was inspired by the Super Cub. However, when the list of improvements to various aspects of the airplane is examined, it’s obvious that not much of the original Cub remains. For instance, the wing structure is highly modified to take advantage of its proven reduction in stall speed via a longer training edge, flaps that are 2 feet longer and 4 inches wider, and the ailerons are shifted toward the tips. The landing gear is its own design with oleo shock struts in place of the bungees. Custom Flight’s kits also come with video directions that don’t miss a trick. The one for building the wings alone, for instance, is 12 hours long!

So, Start Looking

There are a lot of different ways builder/pilots can satisfy their desire for either lounging around in the twilight or charging toward tall trees on takeoff knowing they’ll kangaroo over them. If it has Cub in its name or Cub in its genes, there is someone, somewhere building exactly what almost any wannabe Cubophile could wish for.

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