Main supporting structure of an aircraft lifting surface

A method of manufacturing a main supporting structure of an aircraft lifting surface comprising an upper skin, a lower skin, a front spar, a rear spar, a first set of transverse ribs extended from its front spar to its rear spar and a second set of transverse ribs crossing at least one of the front spar and the rear spar;

• the transverse ribs of the second set being configured with upper and lower recesses in their crossing zones with at least one of the front spar and the rear spar;
• at least one of the front spar and the rear spar being configured with slot holes in their crossing zones with the second set of transverse ribs;
• the method comprising the following steps:
• a) providing the upper skin, the lower skin, the first set of transverse ribs and the second set of transverse ribs as individual elements made up of a composite material;
• b) providing the front spar and the rear spar as individual elements made up of a composite material, divided in first and second parts if they are crossed by at least a rib;
• c) assembling the main supporting structure in the following sub-steps:
• c1) joining all the ribs to the upper skin and to the lower skin;
• c2) joining the front spar and the rear spar to the upper skin and to the lower skin, joining their first parts to the upper skin and their second parts to the lower skin if they are divided in two parts;
• c3) joining the first and second parts of at least one of the front spar and the rear spar between them if they are divided in first and second parts.

A method for manufacturing a main supporting structure of an aircraft lifting surface;

• the main supporting structure comprising upper and lower faces defining its aerodynamic profile and front and rear faces oriented towards respectively the leading and trailing edges, a first set of transverse ribs extended from the front face to the rear face and a second set of transverse ribs crossing at least one of the front face and the rear face;
• the transverse ribs of the second set being configured with upper and lower recesses in their crossing zones with at least one of the front face and the rear face;
• at least one of the front face and the rear face being configured with slot holes in their crossing zones with the second set of transverse ribs;
• the method comprising the following steps:
• a) providing the first set of transverse ribs, the second set of transverse ribs, a first structural element comprising three or two contiguous faces of the main supporting structure and a second structural element comprising the other face or faces of the main supporting structure as individual elements made up of a composite material;
• the first and second structural element comprising connecting flanges between them;
• b) assembling the main supporting structure in the following sub-steps:
• b1) joining all the ribs to the first and second structural elements;
• b2) joining the first and second structural elements between them.