Abstract: The present disclosure provides a keel beam assembly, an aircraft including the keel beam assembly, and a method of aircraft manufacture using the keel beam assembly. An illustrative keel beam assembly comprises a pair of keel chords extending outside an aircraft fuselage and forming at least part of a lower keel box portion of a keel box. An upper keel box portion of the keel box is coupled to the pair of keel chords and has an aft end engaged with and secured to an aft wheel well bulkhead (AWWB).

Abstract: Described herein are aircraft, comprising rear spar integration assemblies, and methods of manufacturing these aircraft. Specifically, an aircraft comprises a keel beam and a center wing box, comprising a rear spar. The rear spar is attached to the keel beam using a rear spar integration assembly. The assembly comprises a rear spar stiffener, attached to the rear spar, and having a stiffener load axis. The assembly also comprises and a keel beam fitting, attached to the keel beam, and having a fitting load axis. The rear spar stiffener is also attached to the keel beam fitting, e.g., using splice plates. More specifically, the fitting load axis is offset relative to the stiffener load axis along the primary axis of the aircraft. This offset is designed to compensate for a bending moment at the keel beam-rear spar interface, which allows reducing the size and/or the number of fasteners needed.

Abstract: Embodiments for aircraft keel beam assembly. One embodiment is a keel beam assembly of an aircraft. The keel beam assembly includes a keel attach chord to connect to a wing center section of the aircraft, the keel attach chord extending in a longitudinal direction between a rear spar and front spar of the aircraft. The keel beam assembly also includes a lower chord disposed underneath the keel attach chord and extending in the longitudinal direction between an aft wheel well bulkhead and a forward bulkhead of the aircraft. The keel beam assembly further includes a forward web to couple the keel attach chord and the lower chord, the forward web including a front edge extending in a diagonal direction from the keel attach chord that is downward and aft toward the lower chord to create an open area forward from the front edge.

Abstract: A fuselage for an aircraft includes a pressure deck assembly extending along a roll axis of the fuselage. The pressure deck assembly includes longitudinal beams and a pressure deck. The longitudinal beams extend lengths along the roll axis of the fuselage. The pressure deck extends between the longitudinal beams along the lengths of the longitudinal beams. The pressure deck is compliant along a pitch axis of the fuselage. The fuselage includes a bulkhead extending along a yaw axis of the fuselage. The bulkhead is joined to the pressure deck assembly at a corner joint. The fuselage includes a compression chord extending a length along the pitch axis of the fuselage. The compression chord is joined between the pressure deck assembly and the bulkhead at the corner joint such that the compression chord extends on an outside of the corner joint.

Abstract: A pressure deck assembly for a fuselage includes a longitudinal beam extending a length along a roll axis of the fuselage. The longitudinal beam includes a central member and opposing first and second flanges extending from the central member. The first flange includes a first upper side and a first lower side. The second flange includes a second upper side and a second lower side. The pressure deck assembly includes a pressure deck that includes first and second deck segments. The first deck segment is joined to the first flange of the longitudinal beam along the first lower side of the first flange. The second deck segment is joined to the second flange of the longitudinal beam along the second lower side of the second flange.

Abstract: Embodiments for hybrid pressure deck of an aircraft. One embodiment is a pressure deck disposed over a main gear wheel well of an aircraft. The pressure deck includes longitudinal beams extending in a forward and aft direction between an aft wheel well bulkhead and a rear spar of the aircraft. The pressure deck also includes a web attached to an underside of the longitudinal beams. The web includes a flat web portion supported by transverse stiffeners extending in an inboard and outboard direction, and a curved web portion including arches configured to flex laterally from load in the inboard and outboard direction. A transition between the flat web portion and the curved web portion extends at least partially in the forward and aft direction of the aircraft.

Abstract: The present disclosure provides a keel beam assembly, an aircraft including the keel beam assembly, and a method of aircraft manufacture using the keel beam assembly. An illustrative keel beam assembly comprises a pair of keel chords extending outside an aircraft fuselage and forming at least part of a lower keel box portion of a keel box. An upper keel box portion of the keel box is coupled to the pair of keel chords and has an aft end engaged with and secured to an aft wheel well bulkhead (AWWB).

Abstract: Embodiments for aircraft keel beam assembly. One embodiment is a keel beam assembly of an aircraft. The keel beam assembly includes a keel attach chord to connect to a wing center section of the aircraft, the keel attach chord extending in a longitudinal direction between a rear spar and front spar of the aircraft. The keel beam assembly also includes a lower chord disposed underneath the keel attach chord and extending in the longitudinal direction between an aft wheel well bulkhead and a forward bulkhead of the aircraft. The keel beam assembly further includes a forward web to couple the keel attach chord and the lower chord, the forward web including a front edge extending in a diagonal direction from the keel attach chord that is downward and aft toward the lower chord to create an open area forward from the front edge.

Abstract: Described herein are aircraft, comprising rear spar integration assemblies, and methods of manufacturing these aircraft. Specifically, an aircraft comprises a keel beam and a center wing box, comprising a rear spar. The rear spar is attached to the keel beam using a rear spar integration assembly. The assembly comprises a rear spar stiffener, attached to the rear spar, and having a stiffener load axis. The assembly also comprises and a keel beam fitting, attached to the keel beam, and having a fitting load axis. The rear spar stiffener is also attached to the keel beam fitting, e.g., using splice plates. More specifically, the fitting load axis is offset relative to the stiffener load axis along the primary axis of the aircraft. This offset is designed to compensate for a bending moment at the keel beam-rear spar interface, which allows reducing the size and/or the number of fasteners needed.

Abstract: An arched gutter that can be used to channel moisture within an aircraft can include an arched web including a plurality of laterally spaced arches. The plurality of arches impart a flexibility to the arched gutter such that the arched gutter has an increased resistance to fatigue cracking and other wear and damage resulting from, for example, parasitic loads due to high bending strains that are transferred to the arched gutter by a wing to which the arched gutter is attached during operation of the aircraft. An aircraft section and an aircraft including the arched gutter are also described.

Abstract: A pressure deck assembly for a fuselage includes a longitudinal beam extending a length along a roll axis of the fuselage. The longitudinal beam includes a central member and opposing first and second flanges extending from the central member. The first flange includes a first upper side and a first lower side. The second flange includes a second upper side and a second lower side. The pressure deck assembly includes a pressure deck that includes first and second deck segments. The first deck segment is joined to the first flange of the longitudinal beam along the first lower side of the first flange. The second deck segment is joined to the second flange of the longitudinal beam along the second lower side of the second flange.

Abstract: A fuselage for an aircraft includes a pressure deck assembly extending along a roll axis of the fuselage. The pressure deck assembly includes longitudinal beams and a pressure deck. The longitudinal beams extend lengths along the roll axis of the fuselage. The pressure deck extends between the longitudinal beams along the lengths of the longitudinal beams. The pressure deck is compliant along a pitch axis of the fuselage. The fuselage includes a bulkhead extending along a yaw axis of the fuselage. The bulkhead is joined to the pressure deck assembly at a corner joint. The fuselage includes a compression chord extending a length along the pitch axis of the fuselage. The compression chord is joined between the pressure deck assembly and the bulkhead at the corner joint such that the compression chord extends on an outside of the corner joint.

Abstract: An arched gutter that can be used to channel moisture within an aircraft can include an arched web including a plurality of laterally spaced arches. The plurality of arches impart a flexibility to the arched gutter such that the arched gutter has an increased resistance to fatigue cracking and other wear and damage resulting from, for example, parasitic loads due to high bending strains that are transferred to the arched gutter by a wing to which the arched gutter is attached during operation of the aircraft. An aircraft section and an aircraft including the arched gutter are also described.