The Potez 58 was equipped with fixed slats on the leading edge of the wing. These are small fixed airfoils designed to prevent airflow at high angles of attack and therefore at low speeds. They increase the lift and thus allow shorter take-offs or avoid stalling.
They delay the upper surface boundary layer stall and allow higher incidences than trailing edge flaps. They therefore had the effect of delaying the air separation by the slit effect and increasing the wing area.
Here they are on pictures of the original Potez 58
A few magnifications on the photos of the aircraft of the time, allowed me to observe that the slats were fixed to the wing with 4 supports. The slats are made of 0.4 mm plywood on the top and bottom of the leading edge of the wing. The bottom surface will be attached to the lower part of the ” slat ribs ” and the top surface to the upper part of these ribs. A diagram will be more telling. Here is the one I made during the sketchup modelling (sorry in French)
The first step was therefore the digital cutting of the supports and ribs.
The top surface of the slat (plywood 0.4 mm) is fixed and pinned to its trailing edge on the work surface. The trailing edge is then glued in position on the 0.4 mm plywood.
Then the rest of the plywood is glued in place, following the shape of the rib. Of course, the plywood is soaked in water beforehand and cyano is strongly recommended to hold it to the rib.
I then cut small pieces of balsa to glue between the ribs at the leading edge. After sanding, they will form the rounded leading edge of the slat
Next, 0.4 mm Plywood (previously hardened) is glued to the inside of the ribs. This forms the underside of the slat. And sanding of the leading edge to obtain the desired roundness
The slat is then covered with 25g/m² fibreglass and glued to the cellulose coating.
Then I glued the supports of the slats which will be fixed on the wing
All that remains is to sand, filler, primer and paint
Le voici présenté sur le profil de l’aile. Reste à le coller
