Beautiful scenery of Shikoku Mountains, reminiscent of the original scenery of Japan
Aviation safety is a key topic among pilots. They engage with it, embrace it, and strive to implement it in their daily aviation routines. For enthusiasts of the Super Cub, Dakota Cub’s Extended Slotted Wing presents an opportunity to enhance safety margins and improve the aircraft’s climb efficiency.
Picture this: flying your Super Cub at a steep angle of attack, with the airspeed indicator showing just 20 mph, entering a 60-degree bank, and starting a climbing spiral while using lower power settings than full throttle! This scenario exemplifies what the Dakota Cub Extended Slotted Wing offers. One of the most notable features of this wing is its ability to maintain full control authority even at higher angles of attack. Gone are the days of mushy controls, losing lift, or dropping a wing.
Mark Erickson, who founded Dakota Cub, started his journey in the 1990s with a simple goal: to create Cub ribs. With Piper parts unavailable at reasonable prices and the fragility of Piper ribs, he opted to manufacture his own. By applying modern technology to the legacy Piper wings, initially designed for the YL-14 variant of the J5C Cub, he innovated significantly. The YL-14 wing, known for its built-up design, was only produced in 14 units before World War II ended, with only two still flying today—one in Spain and another in Nebraska.
The Extended Slotted Wing from Dakota Cub features several enhancements compared to the original Cub wing and the L-14. Erickson reworked the original US35B airfoil used for the L-14 and created a custom “T”-shaped extrusion that matches the ribs used in construction but is lighter, simpler, and stronger than the originals. He successfully acquired the STC for the new wing design in 1993.
The new ribs added a minimal seven pounds to each original Piper wing. Although tested structurally for weights up to 2,200 lbs, the STC restricts the gross weight to 1,750 lbs for the standard wings or 2,000 lbs for those equipped with a Wipaire One Ton Cub STC. Such limitations are anticipated to evolve in future developments. Over the years, Erickson has designed ribs and many other components that gained FAA PMA for all fabric-covered Piper wings. He also received STC for full-length leading-edge slots in 1998 to enhance airflow at lower speeds. Furthermore, he designed square wings, removing the leading edges to increase the surface area by 6%, enhancing folding by 44%, and extending the ailerons by 23 inches toward the wingtips. He dubbed this design “Extended Wing.” This modification adds approximately eight pounds to the original wing.
Incorporating slots into the Extended Wing increases the weight by another nine pounds per wing, yet the enhancement in flight safety is well worth this tradeoff. The flight characteristics of the square and built-up wings, which Erickson refers to as the “Extended Slotted Wing,” significantly enhance the safety and performance of any Cub project. The Extended Slotted Wing is the top-performing wing available from Dakota Cub, featuring a 135-inch slot, square wings with 102-inch ailerons, and a coverage area of 90.25 inches. Dakota Cub also offers traditional Cub wings and square wings without slots.
Essentially, the Extended Slotted Wing is designed for increased safety. It permits higher critical angles of attack and lower stall speeds, effectively minimizing the risk of sudden lift loss in comparison to straight wings. This design delays airflow separation from the wing surface, improving aileron control, so that the primary stall indication is typically a higher descent rate than usual. This characteristic allows pilots to maintain controlled descent rates on landing approaches, enabling more precise touches without the concern of stalling or dropping a wing. It also enhances turning rates thanks to the extended ailerons reaching out to the tips of the wings.
For those looking to maximize the advantages of the Extended Slotted Wing on their Super Cub, it is advisable to install a 3-inch gear extension. This addition will optimize the wings’ slow-speed capabilities during landings, and larger tires can further enhance performance. Short landing gear combined with smaller tires can lead to tail-first landings and longer takeoff runs, as achieving a higher angle of attack becomes more challenging.
