75 years after the Piper Aircraft Corporation was formed, Mr Piper’s Cub – the proto light aeroplane – remains the model for Light Sport Aircraft
Words and images Philip Whiteman
This year marks 75 years of Piper aircraft and the 75th birthday of the J3 Cub, the model that made William Piper ‘the Henry Ford of aviation’. The J3 gained its type certificate in October 1937, just a few weeks before Piper reconstituted the Taylor Aircraft Company as the Piper Aircraft Corporation. While William Piper’s personal drive and unfailing commercial instinct made the Cub the original private light aeroplane and the most popular aircraft of its era, it was actually designed by C Gilbert Taylor, who had established the original Taylor Brothers Aircraft Company in Rochester, New York State with his brother Gordon.
The E2 model that became the first Cub actually appeared in 1930, the fifth in a series of Taylor aircraft that started with A, B and C ‘Chummy’ models. These were relatively expensive high-wing monoplanes with side-by-side seating and radial engines that, although they performed well enough, sold in small numbers in the years leading up to and following the infamous Wall Street Crash.
An angular, parasol-wing, open-cockpit machine, the E2 (‘2’ by the way denoting two seats) was a very much a product of the Depression. The Model D1 that preceded it was a simple open-frame glider. Its wings were incorporated in the E2, which was intended to be as basic an aeroplane as possible. The biggest problem facing Taylor and Piper — an investor who had become increasingly involved in managing the company since its move to Bradford, Pennsylvania in 1928 — was finding a suitable engine. First choice had been a two-cylinder, two-stroke: the 25hp Brownbach Tiger Kitten. This was not a success for, despite the best efforts of the engine manufacturer’s pilot, the E2 could only be persuaded to make a foot-high hop over a distance of around fifteen feet or so. Legend has it that the engine gave the aeroplane its name, when Taylor Aircraft accountant Gilbert Hadrel pointed out that a tiger’s kitten is a cub…
That the E2 Cub would not only fly, but fly well was proved by fitting a nine-cylinder Salmson radial — a 40hp beauty of watch-like quality that worked, but was prohibitively expensive. Salvation arrived in the form of the Continental A40, the flat-four that set the pattern for light aircraft engines that has lasted to this day.
The early A40 was plagued with reliability problems and Continental stopped production for a short period during the early 1930s. Had it not, there might never have been a J-model Cub: in seeking alternative engine suppliers, Taylor worked his way through the F2 Cub (certified with the three-cylinder Aeromarine radial), the G2 (fitted with Taylor’s own flat-four T-40) and the H2 (three-cylinder Szekely radial), before the A40 returned to the market in developed form.
The J2 that came next was essentially a refined version of the E2 (the ‘I’ designation being passed over because the letter might be confused with the numeral 1). The J2 introduced the rounded wing tips and tail surfaces, fully enclosed cabin and raised rear fuselage line that defined the Cub shape so familiar today. Piper had asked a young engineer called Walter Jamoneau to continue development of the J2 while Gilbert Taylor was absent from work, suffering from a long illness. Stressing the already difficult relationship between Piper and Taylor, this led to Taylor’s resignation from the company in December 1935, Piper buying out his 50 per cent shareholding.
Jamoneau subsequently become Chief Engineer and designed the next model, the definitive J3. (Interestingly he chose not to use the K designation, but instead continue the J-series: you have to wonder if there was some element of personal vanity in this.) The J3 was one of the most successful light aircraft ever built. Branching off into other lines, including the ‘short-wing’ Pipers that led to the four-place tricycle-undercarriage Tripacer, the basic two-seat Cub lived on as a Piper product in PA-11 Cub Special and then PA-18 Super Cub form until 1994.
A huge factor in the Cub’s success was the USA-35B aerofoil section, used throughout its production life. The Cub never was a particularly efficient aeroplane, but the high-lift wing section ensures it gets off the ground very quickly and stalls at a remarkably low speed, recovering the instant back-pressure on the stick is released. While there is little aerodynamic stall warning, the height loss can be less than 100ft or so and, depending on the direction of turn, the J3 will either gently flop wings-level or continue to mush around at the same angle of bank. (Nevertheless, US NTSB records show that the otherwise relatively safe Cub does not have an especially good record for stall/spin accidents, presumably because of the temptation to abuse such a docile aircraft in low-flying operations.)
Cubs lend themselves to bush operations. With the appropriate aerodynamic tweaks, a Super Cub can land and take off in a distance that defies credibility — see YouTube for the evidence. You can operate even the low-powered J3 from all but the shortest strips. However, the J3 is not an easy aeroplane to land: the relatively stiff undercarriage, light overall weight and huge wing area all conspire to make it a ‘bouncer’. Its crosswind limits are surprisingly low: one experienced warbird pilot told me that he treated a crosswind component of five knots as his working limit (presumably for tarmac runways, which are best avoided wherever possible).
The PA-18 Super Cub is flown solo from the front seat and is generally reckoned to be easier to fly. As well as having a superior takeoff performance, it is also rather faster — although not that much faster if flown for best economy. On the other hand, the Super Cub has bomber-heavy ailerons (significantly Aviat chose to add aileron ‘spades’ to its Husky development of the PA-18) while the J3 feels quite sprightly in comparison, and in standard 65hp form its 16-18 lph fuel consumption has only in recent years been bettered by Rotax-engined ultralights. The Super Cub is a wonderful aircraft for professional use: the J3 is perhaps the better choice for the less well-heeled Sunday flyer.
So evergreen is the Cub that a number of companies have continued to manufacture kits of parts to build totally faithful J3 replicas, while others have continued production of what is essentially the J3 or Super Cub in developed form. Any number of Cub-inspired kitplanes and ultralights are available, some being near replicas, others resembling the classic Piper only in their general form — the design appears to be timeless. The US Light Sport Regulations are pretty much written around the Cub’s specification.