Flight safety is something every pilot talks about. They live it, accept it and hope to always choose it in their day to day in the world of aviation. For the Super Cub fan, the Dakota Cub’s extended splined wing offers pilots the opportunity to improve their margin of safety, as well as increase the aircraft’s climb performance.

Imagine flying your Super Cub at a high angle of attack with the airspeed indicator reading 20 mph, then rolling into a 60 degree bank and starting an upward spiral while selecting a power setting that is less than full throttle! That’s the typical display that the Dakota Cub Extended Slotted Wing sells. The second most talked about quality of this wing is the ability to have full flight control authority at high angles of attack. No more smooth controls, dropping it or dropping the wing on the stall.

Mark Erickson, the founder of the Dakota Cub, began his mission in the 1990s. All he wanted was a Cub rib. Nothing from Piper was available at a reasonable cost and since Piper’s ribs were so fragile, he decided to build his own. He applied modern technology to an old Piper wing that was originally developed for the YL-14 link version of the J5C Cub. The YL-14 wing was a slotted wing. According to Erickson, only 14 of these aircraft were built before the end of World War II. They were specifically designed for short 100-foot takeoffs and climbs with high angles of attack. There are only two of these still on the air today: one in Spain; the other in Nebraska.

The Dakota Cub extended slotted wing has several variations compared to the original Cub wing and the L-14 wing. Erickson revised the original Piper US35B airfoil used for the L-14. He developed a custom “T”-shaped extrusion with the same dimensions that, when used to build a beam-style rib, is lighter, easier to work with, and stronger than the original wing. Erickson obtained an STC for the new wing in 1993.

Erickson’s new rib only adds seven pounds to the weight of each original Piper wing. The new wing was structurally tested for a 2,200 lb. access, however the STC limits the gross weight to 1,750 lbs. for the original wing or 2,000 lbs. for those wings equipped with the Wipaire One Ton Cub STC. It is to be hoped that this artificial reduction will be changed in the future. In the intervening years, Erickson has designed ribs and many other parts that are FAA PMA approved for all Rag Brim Pipers. Erickson received the STC for the full-length leading edge slot in 1998. This slot helps preserve the boundary layer of airflow at low speeds. On top of that, Erickson designed a boxy wing and got rid of the tip bow, giving the wing an additional 6% surface area, increased the flaps, resulting in 44% more flap area, and pushed the ailerons out 23 inches to the edge of the wing. He calls it the “spread wing.” The square wing adds about 8 pounds to the original Piper wing.

Adding a slot to the extended wing adds another nine pounds per wing, but the added safety envelope to fly from is well worth it. The flight characteristics of the boxy and slotted wing, which Erickson calls the “Extended Slotted Wing”, is the main advantage and emphasis regarding the choice of wings to include on his Cub project. The extended slotted wing is the best performing wing the Dakota Cub offers. It has a 135-inch slot, a square wing with 102-inch ailerons, and a 90.25-inch flap. Dakota Cub also offers the standard Cub brim and a square brim without the slot.

The extended slotted wing is simply a safer wing. It allows for a higher critical angle of attack, slower stall speed, and virtually eliminates sudden stall compared to a straight wing. It retards the airflow separation from the wing surface, so aileron authority is maintained, and in many cases the only sign of a stall will be a higher than normal sink rate. This phenomenon allows the rate of descent of the aircraft on approach to landing to be controlled by power alone, allowing for a more precise touchdown without fear of a wing stalling or falling over to the side. The wing also has improved roll rate due to the ailerons extending to the very end of the wing.

If you want to take full advantage of the extended splined wing on your Super Cub, installing a 3-inch gear extension is recommended. The gear extension will allow the low speed capabilities of the wing to take full effect when landing. Bigger tires will take care of this too. A short gear coupled with small tires will result in tailwheel first landings and a longer than optimal takeoff run because it’s harder to achieve that higher angle of attack.

The end result of all this innovation is a Cub that has better climb performance, better descent control, slower landings, and a much greater margin of safety. A widebody fuselage from Airframes, Inc features an extended fuselage, and when combined with the larger control surfaces and slot, a pilot can fly with a 45 degree nose-up attitude, land at 25 knots and still have a wing hanging in the air.