Cul de canard and popular with anglers and trout alike. The use of CDC's in fly fishing originated from the Jura Mountains during the 1920s where fly fishermen used this feather in dry flies to aid buoyancy in a particular pattern called Moustique. It took until the 1980s for popular use of this feather within a whole range of patterns. Cul de canard Cul de canard (CDC) (French for "duck bottom") are the feathers from the back of a duck directly around the preen gland (uropygial gland); they are very buoyant due to preen oil produced by the preen gland. They are used
Canard (aeronautics) creates a vortex which attaches to the upper surface of the wing, stabilising and re-energising the airflow over the wing and delaying or preventing the stall. The canard foreplane may be fixed as on the IAI Kfir, have landing flaps as on the Saab Viggen, or be moveable and also act as a control-canard during normal flight as on the Dassault Rafale. A close-coupled canard has been shown to benefit a supersonic delta wing design which gains lift in both transonic flight (such as for supercruise) and also in low speed flight (such as take offs and landings). A free-floating