Patent ID: 7413140

Claim:
A rotary wing aircraft comprising a crew cabin, a passenger compartment rearward of the cabin in a direction from a nose to a tail of the aircraft, a force-transmission structure below the cabin, a steerable nose undercarriage connected to said force-transmission structure, and a fairing of a fuselage formed, at least in part, by top and bottom covering segments that are adjacent to said force-transmission structure, the force-transmission structure comprising: a rigid arrangement extending substantially in an elevation direction; a structural bottom floor rigidly connected to a bottom of the rigid arrangement; and a machine top floor rigidly secured at a top of the rigid arrangement; wherein, in longitudinal elevation view, the force-transmission structure forming an L-shape, wherein the arrangement includes a transversely centered box, and wherein the top and bottom covering segments are such that the forces introduced by said nose undercarriage are distributed within the force-transmission structure and are transmitted, at least in part, by the force-transmission structure to the top and bottom covering segments, and wherein the structural bottom floor comprises: two longitudinal spars extending longitudinally forwards from a bottom base of the arrangement; and two transverse spars disposed substantially transversely at right angles relative to the box, one of the transverse spars being longitudinally in front of the box and the other transverse spar being substantially vertically aligned with a rear face of the box; and wherein the arrangement further includes two lateral arms extending substantially in elevation upwards from the rear of the structural bottom floor on either side of the box, the two lateral arms are arranged at a distance from the box so as to form with the box a transverse passage on either side of the box for movement between the cabin and the passenger compartment and for visibility between the cabin and passenger compartment.