embodiments the thickness of the skin changes slowly linearly without stages so as not to require any ply drop off area note however that certain plies or jumps in thickness are necessary whatever the aircraft in effect certain special areas of the fuselage require jumps in thickness like the longitudinal and circumferential joining areas and opening areas hatches doors inspection ports these jumps in thickness create a variation in thickness on the interior profile of the skin requiring the use of specific parts these jumps in thickness are present on all aircraft whatever the technology for manufacturing said aircraft the disclosed embodiments on the other hand makes it possible to avoid the ply drop off to make the changes in skin thickness necessary to absorb the flexural forces of the fuselage to do so the disclosed embodiments propose replacing the ply drop off areas with a continuous variation in the thickness of the skin fig7 8 and 9 show examples of changes in the skin thickness profile fig7 shows a schematic sectional view of a fuselage panel 3 made of composite material on the left part 30 of this panel which corresponds to the nose of the aircraft the skin thickness is 1 4 mm on the right lateral part 32 of this panel which corresponds to the wing side of the aircraft the skin thickness is 2 1 mm on the edge 33 of this panel the thickness is 3 5 mm making such a fuselage panel 3 of composite material requires two frame molds and two stringer molds one frame mold for area 30 one frame mold for area 32 one stringer mold for area 30 and one stringer mold for area 32.