# US 12,110,094 B2 · Keel beam assembly for an aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,094 B2 - Document ID: US12110094B2 - Status: Granted - Kind: B2 - Application number: 17/579,241 - Filed: 2022-01-19 - Published: 2022-07-21 - Granted: 2024-10-08 - Earliest claimed: 2021-01-20 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Danilo Vukosav; Daniel Cox; Evgeny M. Potupchik; James David Tummons; Ryan Matthew Slater; Timothy R. Portway - Web page: https://patentgrep.com/patent/US12110094B2 ## CPC - B64C 1/26: Attaching the wing or tail units or stabilising surfaces - B64C 1/064: {Stringers; Longerons} - B64C 1/069: {Joining arrangements therefor} - B64C 1/10: Bulkheads - B64C 25/04: Arrangement or disposition on aircraft - B64C 2025/125: {into the fuselage, e.g. main landing gear pivotally retracting into or extending out of the fuselage} - B64C: AEROPLANES; HELICOPTERS ## 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). ## Claims ### Claim 1 A keel beam assembly, comprising: 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; and an upper keel box portion of the keel box coupled to the pair of keel chords and having an aft end engaged with and secured to an aft wheel well bulkhead (AWWB), wherein the AWWB includes a web, the upper keel box portion having a pair of side portions spaced laterally from one another, and an upper portion connecting the pair of side portions, wherein the pair of side portions are separately secured through the web to a backup structure engaged with an aft side of the web. ### Claim 2 (depends on 1) The keel beam assembly of claim 1, wherein an aft portion of the keel box has a center of mass located within 10 centimeters of an envelope defined by an exterior surface of a skin of the aircraft fuselage. ### Claim 3 (depends on 1) The keel beam assembly of claim 1, wherein the upper keel box portion is bolted to the AWWB. ### Claim 4 (depends on 1) The keel beam assembly of claim 1, secured to a peripheral portion of the aircraft fuselage. ### Claim 5 (depends on 4) The keel beam assembly of claim 4, wherein the keel box includes a body and one or more brackets fastened to the body, and wherein each bracket has one or more flanges engaged with the web of the AWWB and defining apertures through which the bracket is secured to the backup structure through the web using fasteners. ### Claim 6 (depends on 1) The keel beam assembly of claim 1, further comprising a pair of aft chord extensions spliced to the pair of keel chords at aft ends of the keel chords and extending outside the aircraft fuselage. ### Claim 7 (depends on 1) The keel beam assembly of claim 1, wherein the AWWB includes a web and a horizontal stiffener located on a forward side of the web, and wherein the upper keel box portion is engaged with and fastened to the horizontal stiffener. ### Claim 8 (depends on 1) The keel beam assembly of claim 1, further comprising a clip having a first portion mounted to the keel box at one of the keel chords and a second portion engaged with and secured to a forward side of the AWWB. ### Claim 9 (depends on 1) The keel beam assembly of claim 1, wherein the upper keel box portion is welded to the AWWB. ### Claim 10 An aircraft, comprising: a fuselage; an aft wheel well bulkhead (AWWB) including a web; a keel beam assembly including a pair of keel chords extending outside the fuselage and forming at least part of a lower keel box portion of a keel box, the keel beam assembly also including an upper keel box portion of the keel box coupled to the pair of keel chords and having an aft end mounted onto a forward side of the web of the AWWB; and a backup structure engaged with an aft side of the web and secured to a peripheral portion of the fuselage, wherein; the upper keel box portion has a pair of side portions spaced laterally from one another; and each side portion is separately bolted through the web to the backup structure. ### Claim 11 (depends on 10) The aircraft of claim 10, further comprising a pair of aft chord extensions spliced to the pair of keel chords at aft ends of the keel chords and extending outside the fuselage. ### Claim 12 (depends on 10) The aircraft of claim 10, wherein an aft portion of the keel box has a center of mass located within 10 centimeters of an envelope defined by an exterior surface of a skin of the fuselage. ### Claim 13 (depends on 10) The aircraft of claim 10, wherein each side portion is bolted through the web to a respective vertical beam of the backup structure. ### Claim 14 (depends on 10) The aircraft of claim 10, wherein the keel box includes a body and one or more brackets fastened to the body, and wherein each bracket has one or more flanges engaged with the AWWB and defining apertures through which the bracket is mounted onto the AWWB. ### Claim 15 (depends on 10) The aircraft of claim 10, wherein the backup structure includes a vertical beam. ### Claim 16 (depends on 10) The aircraft of claim 10, wherein the aft end of the upper keel box portion is bolted to the backup structure, the backup structure being secured against the aft side of the web. ### Claim 17 (depends on 10) The aircraft of claim 10, wherein the backup structure is comprised of a left vertical beam and a right vertical beam. ### Claim 18 A method of aircraft manufacture using an aircraft section including a fuselage portion coupled to a pair of keel chords, wherein the keel chords extend outside the fuselage portion, form at least part of a lower keel box portion of a keel box, and are coupled to an upper keel box portion of the keel box, the method comprising: mounting an aft end of the upper keel box portion onto a forward side of an aft wheel well bulkhead (AWWB), wherein the AWWB includes a web, and wherein mounting includes bolting the upper keel box portion through the web of the AWWB to a vertical beam located on an aft side of the web. ### Claim 19 (depends on 18) The method of claim 18, wherein the aircraft section is a first aircraft section, the method further comprising coupling the AWWB to a fuselage portion of a second aircraft section prior to mounting. ### Claim 20 (depends on 18) The method of claim 18, wherein mounting comprises positioning the keel box such that no part of the keel box extends through the web.