The evolution of propeller-driven airplanes was accompanied by a permanent growth of their engine power. It proceeded in two directions – by increasing the engine speed and by increasing the propeller diameter. The first way was more suitable for high-speed bomber-fighters, whereas for a comparatively low-speed airplane, such as an attack plane, this way proved to be unpromising. For the powerful engine of a low-speed airplane to work with the maximal efficiency, it is necessary to use as large-diameter propeller.

The following contradiction occurs.
The struts of the wing's landing gear must be long enough to prevent the propeller from touching the land. At the same time, the long struts are heavy. With the great length of the struts, their strength can be preserved by abruptly increasing their thickness.
Designers opted to use a spatial approach in solving this contradiction.

The wings of such airplanes as the American carrier plane F4U Corsair or German dive-bomber Ju-87 were bent at the point of attachment to the landing gear. In that point, the wing maximally approached the land. This allowed the landing gear struts to be made very short, which ensured a low weight of the strut at its high reliability.