Flight safety is what all pilots talk about. They live, accept it and always hope to choose it in their daily lives in the world of aviation. For Super Cub fanatics, Extended Slotted Wing from Dakota Cub offers pilots the opportunity to increase their safety margin, as well as to improve the performance of lifting the aircraft.
Imagine that you are flying over a Super Cub at a high angle of attack with a speed indicator at a speed of 20 miles per hour, then roll 60 degrees and start climbing in a spiral, choosing a power setting that is less than a full throttle! This is a typical exhibit in which the Dakota Cub Extended Slotted Wing is sold. The second, most often talked about the quality of this wing, is the ability to have full control over the flight at a high angle of attack. No more soft controls, do not slip down or the wing does not fall on the stall.
Mark Erickson, founder of the Dakota Cub, began his mission in the 1990s. All he wanted was a rib. None of the Piper was available at a reasonable price, and since the ribs of Piper were so fragile, he decided to build his own. He applied modern technology to the old Piper wing, which was originally designed for the LL-14 version for the J5C Cub. The wing of the YL-14 was a rubberized wing. According to Erickson, only 14 of these aircraft were built before the end of World War II. They were specifically designed for short takeoffs at 100 feet and raised from high angles of attack. Now only two of them are still in the air - one in Spain; another in Nebraska.
The Dakota Cub Extended Slotted Wing has several differences compared to the original Cub wing and L-14 wing in this respect. Erickson revised the original Piper US35B aerodynamic profile used for the L-14. He developed the usual extrusion with a T-shape with the same dimensions that when used in the construction of ribs in the style of the farm easier, easier to work and more durable than the original wing. Erickson received the STC for the new wing in 1993.
The new Erickson rib adds seven pounds to the weight of each original Piper wing. The new wing was subjected to structural testing with access to 2,200 pounds, but the STC limits the gross weight to 1,750 pounds for the original wing or 2,000 pounds for those wings that are equipped with a Wipaire One Ton Cub STC. This artificial reduction will hopefully be changed in the future. Over the years, Erickson has developed ribs and many other details that are FAA PMA-ed for all wings with rag wings. In 1998, Erickson was awarded the STC for the full-size cutting edge. This slot helps to keep the airflow boundary layer at slow speeds. In addition, Erickson developed a square wing and got rid of the tip, giving the wing an additional surface area of 6%, increased flaps, which increased the wing area by 44% and pushed the ailerons outward by 23 inches. He calls this "Extended Wing." The square wing adds about 8 pounds to the original Piper wing.
Adding a slot to the extended wing adds another nine pounds to the wing, but the increased protective shell from which to fly can be well worth the compromise. The flight characteristics of the square and slotted wing, which Erickson calls the “extended broken wing”, are a major advantage and emphasis on the choice of wings for inclusion in your Cub project. An extended broken wing is the most efficient wing offered by the Dakota Cub. It has a 135-inch slot, a square wing with 102-inch ailerons and a 90.25-inch flap. The Dakota Cub also offers a standard Cub wing and a square wing without a slot.
An extended broken wing is simply a safer wing. It allows for a higher critical angle of attack, a slower stall speed and virtually eliminates the sudden loss of lift, rather than a straight wing. This delays the separation of the air flow from the surface of the wing, so the authority of the ailerons is maintained, and in many cases the only sign of a stall will be a higher normal level of decency. This phenomenon makes it possible to reduce the speed of the plane’s immersion when approaching landing using power that allows a more accurate landing point without fear that the wing will stop or fall on one side. The wing also has an improved roll speed due to the elongation of the ailerons to the end of the wing.
If you want to make full use of the extended broken wing on the Super Cub, then it is recommended to install a 3-inch extension. Expansion of gearing will allow the possibility of a slow wing speed to fully influence the landing. Large tires will also provide this. Short gear in combination with small tires will lead to the first seats of the tail wheel and the span, which is longer than the optimum, because it is much harder to achieve a higher angle of attack.
The end result of all this innovation is the Cub, which has better lifting characteristics, better flow control, slower landings and a much higher level of safety. The wide-body fuselage from Airframes, Inc has an expanded fuselage, and in combination with larger control surfaces and a gap, the pilot can fly at a 45-degree nasal orientation, land at 25 knots and still have a wing that hangs in the air.
