Floor made out of composite material and process for manufacturing such a floor

1. An aircraft having a floor that can be attached to a vertical frame structure of the aircraft, comprising:

first and second longitudinal beams connected to the frame structure, the longitudinal beams being spaced apart from each other and arranged parallel to each other, each beam having an open side facing the other beam, and

a boxed horizontal structure nested inside the open side of each longitudinal beam so that the longitudinal beams attach the boxed horizontal structure to the frame structure,

the boxed horizontal structure including a plurality of horizontally extending boxes made of composite materials positioned side by side forming a continuous, uniform upper surface and lower surface, each of the boxes extending laterally from a first end nested inside the first longitudinal beam to a second end nested inside the second longitudinal beam, with the upper surface of the boxed horizontal structure covered with an upper skin and the lower surface covered with a lower skin.

2. The aircraft in claim 1 , comprising fittings connecting the beam to the frame structure.

3. The aircraft in claim 2 , wherein the fittings provide pivot connections between the boxed structure and the frame structure.

4. The aircraft in claim 2 , wherein the fittings are made of a composite material.

5. The aircraft in claim 2 , including vertical support rods extending downwardly from the lower surface of the boxed horizontal structure.

6. The aircraft in claim 1 , wherein the longitudinal beam has a C-shaped profile.

7. The aircraft in claim 1 , wherein the longitudinal beam is made of a composite material.

8. A process for manufacturing an aircraft according to claim 1 , including the following operations:

manufacturing boxes from composite materials,

assembling the boxes side by side to form at least one continuous, uniform upper surface,

applying an upper skin and a lower skin made of composite materials to the boxes,

connecting the boxes and the upper and lower skins to form a boxed structure,

arranging a first and second longitudinal beam spaced apart from each other and arranged parallel to each other, each beam having an open side facing the other beam,

installing the boxed structure inside the open side of each longitudinal beam such that each of the boxes extend laterally from a first end nested inside the first longitudinal beam to a second end nested inside the second longitudinal beam,

attaching longitudinal beams to the vertical frame structure of the aircraft.

9. A floor for an aircraft, comprising:

first and second horizontal longitudinally extending beams spaced apart from each other and arranged parallel to each other, each beam having an open side facing the other beam, and

a boxed horizontal structure nested inside the open side of each longitudinal beam such that the longitudinal beam supports the boxed horizontal structure,

the boxed horizontal structure including a plurality of horizontally extending boxes made of composite materials positioned side by side forming a continuous, uniform upper surface and lower surface, each of the boxes extending laterally from a first end nested inside the first longitudinal beam to a second end nested inside the second longitudinal beam, with the upper surface of the boxed horizontal structure being covered with an upper skin and the lower surface covered with a lower skin.

10. The floor in claim 9 , wherein each longitudinal beam has a C-shaped profile.

11. The floor in claim 9 , wherein each longitudinal beam is made of a composite material.