# US 10,864,983 B2 · Rib arrangement in a wing tip device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,864,983 B2 - Document ID: US10864983B2 - Status: Granted - Kind: B2 - Application number: 15/889,383 - Filed: 2018-02-06 - Published: 2018-08-23 - Granted: 2020-12-15 - Earliest claimed: 2017-02-17 - Assignees: Airbus Operations GmbH - Applicants: Airbus Operations Limited - Inventors: Richard Hewson; William Tulloch - Web page: https://patentgrep.com/patent/US10864983B2 ## CPC - B64C 23/069: {using one or more wing tip airfoil devices, e.g. winglets, splines, wing tip fences or raked wingtips} - B64C 3/187: {Ribs} - B64F 5/00: Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing or inspecting aircraft components, not otherwise provided for - B64C 3/58: provided with fences or spoilers (adjustable for control purposes B64C9/00) - Y02T 50/10: Drag reduction - B64C: AEROPLANES; HELICOPTERS - B64F: GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An aircraft (1) having a wing (3) and a wing tip device (4) at the tip of the wing (3), wherein the wing tip device (4) includes a rib (16) positioned in a span wise region (C) of the wing tip device (4) in which transonic flow occurs when the aircraft (1) is in flight. A method of designing an aircraft (1) including predicting where transonic flow occurs on the wing tip device (4) when the aircraft (1) is in flight, and designing the wing tip device (4) with a rib (16) positioned in the span wise region (C) of the wing tip device (4) in which the predicted transonic flow occurs. ## Claims ### Claim 1 An aircraft comprising: a wing, and a wing tip device at a tip of the wing, wherein the wing tip device includes a rib positioned in a span wise region of the wing tip device where a shock wave occurs on the wing tip device when the aircraft is at a cruise altitude and a cruise speed. ### Claim 2 (depends on 1) The aircraft according to claim 1 wherein the cruise speed is in a range of Mach 0.80 to Mach 0.89 and the cruise altitude is in a range of 30,000 feet to 43,000 feet. ### Claim 3 (depends on 1) The aircraft according to claim 1, wherein the wing tip device comprises a pair of spars that are spaced apart in the chord wise direction and wherein the rib links the pair of spars. ### Claim 4 (depends on 1) The aircraft according to claim 1, wherein the rib forms an outboard rib and the wing tip device further comprises an inboard rib. ### Claim 5 (depends on 4) The aircraft according to claim 4, wherein the wing tip device includes a pair of spars lined by the inboard rib. ### Claim 6 (depends on 1) The aircraft according to claim 1, wherein the wing tip device comprises a winglet. ### Claim 7 A wing tip device configured to attach to a tip of an aircraft wing, the wing tip device including a rib positioned in a span wise region of the wing tip device in which transonic flow occurs when the aircraft is in flight. ### Claim 8 An aircraft comprising: a wing, and a wing tip device at a tip of the wing, wherein the wing tip device comprises: a pair of spars that are spaced apart in the chord wise direction, an inboard rib linking the pair of spars, and an outboard rib linking the pair of spars, wherein the outboard rib is positioned in a span wise region of the wing tip device in which a shock wave forms during transonic flow occurs when the aircraft is at a cruise altitude and a cruise speed. ### Claim 9 (depends on 8) The aircraft according to claim 8 wherein the cruise speed is in a range of Mach 0.80 to Mach 0.89 and the cruise altitude range of 30,000 feet to 43,000 feet. ### Claim 10 A method of designing an aircraft including a wing and a wing tip device at a tip of a fixed wing portion of the wing, the method comprising: (i) predicting where a shock wave occurs on the wing tip device when the aircraft is at a cruise speed, and (ii) designing the wing tip device with a rib positioned in the span wise region of the wing tip device in which the predicted shock wave occurs. ### Claim 11 (depends on 10) The method of designing an aircraft according to claim 10 wherein step (i) comprises predicting where transonic flow occurs on the wing tip device when the rib is not in place and wherein the method comprises: (iii) repeating step (i) with the rib in place, to obtain a revised prediction; (iv) repeating step (ii) to locate the rib at the revised location; and (v) iteratively repeating steps (iii) and (iv) until a final design is obtained. ### Claim 12 (depends on 11) The method of designing an aircraft according to claim 11 further comprising manufacturing an aircraft wherein a wing of the aircraft includes a wing tip device embodying the design of the wing tip device. ### Claim 13 (depends on 10) The method of claim 10, wherein the step of predicting a shock wave accurately predicts a span wise region of the wing tip device where a shock wave occurs on the wing tip device while the aircraft is flying at the cruise speed and cruise altitude. ### Claim 14 A method of designing a wing tip device for an aircraft, the method comprising: (i) predicting where a shock wave occurs on the wing tip device when the aircraft is at a cruise speed and at a cruise altitude, and (ii) designing the wing tip device with a rib positioned in a span wise region of the wing tip device in which the predicted shock wave flow occurs. ### Claim 15 (depends on 14) The method of designing a wing tip device according to claim 14 wherein step (i) comprises predicting where transonic flow occurs on the wing tip device when the rib is not in place and wherein the method comprises: (iii) repeating step (i) with the rib in place, to obtain a revised prediction; (iv) repeating step (ii) to locate the rib at the revised location; and (v) iteratively repeating steps (iii) and (iv) until a final design is obtained. ### Claim 16 (depends on 14) The method designing a wing tip device according to claim 14 and further comprising manufacturing a wing tip device embodying the design of the wing tip device. ### Claim 17 (depends on 14) The method of claim 14, wherein the cruise speed in a range of Mach 0.80 to Mach 0.89, and the cruise altitude is in a range of 30,000 feet to 43,000 feet.