Pilots talk about flight safety. Pilots live it, accept and strive to make it a part of their daily lives in aviation. The Dakota Cub Extended Slotted Wing is a great option for Super Cub fans. It allows pilots to increase their safety margin and improve the aircraft’s climb performance.
Imagine your Super Cub flying at a high angle with the airspeed indicator reading 20 MPH, rolling into 60 degrees of bank, and then initiating a climbing spiral. You will also choose a power setting that is less than half throttle. This is how the Dakota Cub Extended Slotted Wing is sold. This wing’s second most popular feature is its ability to maintain full control at high angles of attack. There are no soft controls, plopping the wing down or wing dropping on stall.
Dakota Cub founder Mark Erickson began his mission in 1990. He wanted a Cub rib. Piper was not affordable and the Piper ribs were too fragile so he built his own. He used modern technology to a Piper wing originally designed for the YL-14 Liaison version of the J5C Cub. The YL-14 wing was a slotted wing. Erickson claims that only 14 of these aircraft were built prior to the end of World War 2. These aircraft were designed for 100-foot take-offs and climbs at high angles of attack. Only two of these are still in use today, one in Spain and the other in Nebraska.
The Dakota Cub Extended Slottedwing has many differences when compared to both the original Cub wings and the L-14 wings. Erickson modified the Piper US35B Airfoil that was used in the L-14. Erickson created a “T”-shaped extrusion that is lighter and easier to use in building a truss style rib. Erickson received a Special Trade Certificate (STC) for the new wing.
Erickson’s new Rib only adds seven pounds to each original Piper Wing. The new wing has been structurally tested up to 2,200 lbs. However, the STC limits the gross mass to 1,750 lbs for the original wings and 2,000 for wings with the Wipaire One-Ton Cub STC. This artificial weight reduction will, hopefully, be corrected in the future. Erickson designed ribs, and other parts that can be FAA PMA-ed by all rag-wing Pipers over the years. Erickson received the STC in 1998 for the full-length slot at the leading edge. This slot preserves the boundary layer of airflow at low speeds. Erickson also designed a squared-off wing, eliminating the tip bow, giving the wing an additional 6 percent surface area. He increased the flaps, which resulted in 44% more flap area. The ailerons were moved 23 inches to the edge of Erickson’s wing. It is called the “Extended Wing”. The original Piper wing is 8 lbs heavier with the squared wing.
The Extended Wing’s slot adds nine pounds to each wing. However, the safety margin is well worth it. Erickson refers to the “Extended Slotted Wing” as the main advantage in choosing which wings to include in your Cub project. Dakota Cub’s best-performing wing is the Extended Slotted Wing. It features a slot of 135 inches, a squared-off, 90.25-inch flap, and a wing with 102 inch ailerons. Dakota Cub offers the standard Cub wings and the squared-off wings without the slot.
Extended Slotted Wings are safer than straight wings. The Extended Slotted Wing allows for a greater critical angle of attack and slower stall speed. It virtually eliminates sudden loss of lift compared to straight wings. This delays the separation between the airflow and the wing surface. In many cases, the only sign that there is a stall is a faster-than-normal rate or descent. This allows for the aircraft’s sink rate to be controlled solely by power, allowing it to land at a precise point and avoid wing stalling. Ailerons at the ends of the wings have an increased roll rate, which allows for a wing to glide more smoothly.
A 3-inch extension to your gear is recommended if you want to fully take advantage of the Extended Slotted Wing feature on your Super Cub. This will enable the wing’s slow speed capabilities to fully take effect upon landing. This will also be possible with larger tires. Combining small tires with a short gear will lead to tail wheel first landings. This is because it is more difficult to attain the higher angle of attack.
All this innovation has resulted in a Cub with better climb performance, sink control, faster landings and a greater safety margin. Airframes Inc’s wide-body fuselage features an extended fuselage. This, combined with the larger control surfaces, slot, allows a pilot to fly at 45 degrees nose-up, at 25 knots, while still having a wing that hangs in midair.