A fastening system having differentiable components includes a first fuse pin with a first mating figure and being configured to shear upon the application of a first predetermined load and a first receiver with a second mating feature. The first and second mating features correspond and permit the insertion of the first fuse pin into the first receiver to selectively connect components. The system may include a second fuse pin having a third mating feature and being configured to shear upon the application of a second predetermined load, which may differ from the first predetermined load. The second fuse pin having a third mating feature that prevents the insertion of the second fuse pin into the first receiver. The first fuse pin may be configured to connect together components of a first aircraft and the second fuse pin may be configured to connect together components of a different aircraft.

A fuel tank and a differential frame in a fuselage airframe of a helicopter, the fuel tank being installed between the fuselage lower cover shell and the floor panel. The differential frame separates the fuel tank into two individual compartments, the differential frame having a web below the floor panel with a variable-height with a minimum height at the symmetry axis of the fuselage cross-section and a maximum height at lateral frame roots regions. A transversal beam is attached at each of its both ends to the differential frame bridging the entire variable-height of the differential frame and the fuel tank with two front and rear fuel bladders covering both individual tank compartments with a middle bladder installed between the transversal beam and the variable-height web of the differential frame.

An energy-absorbing (EA) beam member and having a cell core structure is positioned in an aircraft fuselage proximate to the floor of the aircraft. The cell core structure has a length oriented along a width of the fuselage, a width oriented along a length of the fuselage, and a depth extending away from the floor. The cell core structure also includes cell walls that collectively define a repeating conusoidal pattern of alternating respective larger and smaller first and second radii along the length of the cell core structure. The cell walls slope away from a direction of flight of the aircraft at a calibrated lean angle. An EA beam member may include the cell core structure and first and second plates along the length of the cell core structure on opposite edges of the cell material.

A fuselage structure for a rotorcraft (1), the structure comprising load-bearing members including middle frames (9a, 9b) carrying a top floor (12a) and a middle floor (12b). The middle floor (12b) internally partitions the fuselage into two compartments (6, 7), including a cabin-forming top compartment (6) and a bottom compartment (7) having an open bottom (23) leading to the outside via the bottom face of the fuselage. The middle floor (12b) provides a loading plane in the top compartment (6) having a false-floor (27) made up of interchangeable slabs (28) fitted out in a variety of ways. The middle floor (12b) also forms an anchor member from which equipment (16, 17) for suspending can be suspended, which equipment is accessible from outside the fuselage through said open bottom (23).

A device for absorbing kinetic energy for an aircraft structural element undergoing a dynamic impact. The device includes an outer enclosure made from a braided composite material configured to preserve its integrity after an impact, a foam core, contained in the outer enclosure and to at least partially fill the outer enclosure. The foam core is configured to at least partially absorb the kinetic energy generated by the impact. Reinforcing elements are integrated at least partially into the foam core to dissipate, combined with the form core, the kinetic energy generated by the impact. The reinforcing elements includes discontinuous threads inserted into the foam core by stitching, and each discontinuous thread includes an L- or T-shaped head, folded down outside the outer enclosure.

A module an aircraft fuselage includes a support device including a lower end for connection to a fuselage structure in a lower deck of the fuselage, an upper end for connection to an intermediate floor in the fuselage, and an energy absorption element between the upper end and the lower end. A wall panel is connected to the support device and extends along a longitudinal axis and a circumferential direction. In case of a defined crash of an underside of the aircraft fuselage, the energy absorption element is configured to undergo a defined plastic deformation and absorb a defined amount of kinetic energy of that a part of the fuselage structure connected to the lower end of the support device. The plastic deformation and amount of absorbed energy are of a magnitude that in case of defined crash, the module is configured where the fuselage structure will, at the underside of the aircraft fuselage, deform no more than a minimum height.

A reinforced structure is disclosed which includes a structural component as well as a reinforcing part that is arranged in a cavity of the structural component. The reinforcing part can include a support part and a connection, the support part being arranged in the cavity such that a distance between the support part and the structural component at a position of the structural component with a higher probability of deforming under a force load from outside on the structural component is shorter than at a position of the structural component with a lower probability of deforming under a force load from the outside.

A crash load distribution structure of a fuselage, includes a floor frame defining a fuselage floor, a skid member fastened to the lower portion of the floor frame, and a crash box coupled to the skid member and extending to the lower portion of the floor frame, and configured to selectively deform in a crash load direction when an oblique crash occurs thereto.

An aircraft fuselage structure, includes a circumferential reinforcing frame (2) and a plurality of stringers (3) substantially perpendicular to the frame. The frame includes a mechanically weakened area able to cause its localized buckling under the effect of a compressive force exerted circumferentially thereon. The structure includes an energy absorbing device (5) having two effector members (52) secured to the frame respectively on either side of the weakened area, and a central core (51) maintained between the effector members such that a reduction in the distance between the effector members produces a deformation of the central core, which is able to absorb energy under the effect of the deformation.

An aircraft, such as a rotorcraft, may have at least one area designated to house at least one fuel cell and at least one aircraft structure that may translate, during a drop impact of the aircraft, into the area designated to house the fuel cell. At least one shaped fuel cell may be provided and deployed therein, in accordance with the present systems and methods. Each respective shaped fuel cell may define at least one respective through-voids defined through the respective shaped fuel cell, and/or at least one respective edge cavity defined along an edge of the shaped fuel cell, wherein the respective through-void and/or the respective edge cavity correspond to the respective aircraft structure that may translate, during the drop impact of the aircraft, into the area of the aircraft designated to house the respective fuel cell to receive and accommodate the respective structure during the drop impact.