# US 2015/0102162 A1 · Quiet landing gear door > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0102162 A1 - Document ID: US20150102162A1 - Status: Published application - Kind: A1 - Application number: 14/578,473 - Filed: 2014-12-21 - Published: 2015-04-16 - Earliest claimed: 2012-11-30 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Robin B. Langtry; Drew A. Wetzel - Web page: https://patentgrep.com/patent/US20150102162A1 ## CPC - B64C 25/001: {Devices not provided for in the groups B64C25/02 - B64C25/68} - B64C 23/005: {by other means not covered by groups B64C23/02 - B64C23/08, e.g. by electric charges, magnetic panels, piezoelectric elements, static charges or ultrasounds} - B64C 25/16: Fairings movable in conjunction with undercarriage elements - B64C 2025/003: {Means for reducing landing gear noise, or turbulent flow around it, e.g. landing gear doors used as deflectors} - B64C: AEROPLANES; HELICOPTERS ## Abstract A quiet landing gear door and methods are presented. A landing gear door comprises a trailing edge and a leading edge and is operable to deploy to a landing gear door deployed position. A door flap comprises the trailing edge and is hinged to the landing gear door. The door flap deflects toward a landing gear strut to a door flap deployed position in response to deployment of the landing gear door. A leading edge section comprises the leading edge and is coupled to the door flap. The leading edge section deflects toward the landing gear strut to a leading edge deployed position in response to deployment of the landing gear door. ## Claims ### Claim 1 A quiet landing gear door comprising: a landing gear door comprising a trailing edge and a leading edge and deployable to a landing gear door deployed position; a door flap comprising the trailing edge and hinged to the landing gear door to deflect toward a landing gear strut to a door flap deployed position when the landing gear door is deployed to the landing gear door deployed position; and a leading edge section comprising the leading edge and coupled to the landing gear door to deflect toward the landing gear strut to a leading edge section deployed position when the landing gear door is deployed to the landing gear door deployed position. ### Claim 2 (depends on 1) The quiet landing gear door of claim 1, wherein the leading edge section in the leading edge section deployed position and the door flap in the door flap deployed position are configured to reduce a flow velocity on a pressure side of the landing gear door reducing a landing gear wake-wing flap interaction noise. ### Claim 3 (depends on 2) The quiet landing gear door of claim 2, wherein a nominal door flap deflection angle is below 30 degrees. ### Claim 4 (depends on 2) The quiet landing gear door of claim 2, wherein the leading edge section in the leading edge section deployed position and the door flap in the door flap deployed position are configured to reduce the landing gear wake-wing flap interaction noise generated by a landing gear wake-wing flap interaction. ### Claim 5 (depends on 4) The quiet landing gear door of claim 4, wherein the leading edge section in the leading edge deployed position and the door flap in the door flap deployed position are configured to reduce a landing gear wake impinging on a pressure side of a wing flap reducing the landing gear wake-wing flap interaction and the landing gear wake-wing flap interaction noise. ### Claim 6 (depends on 5) The quiet landing gear door of claim 5, wherein the landing gear wake-wing flap interaction reduction is configured to increase effectiveness of the wing flap. ### Claim 7 (depends on 1) The quiet landing gear door of claim 1, wherein the door flap is located at a percent of a chord plane of the landing gear door. ### Claim 8 (depends on 1) The quiet landing gear door of claim 1, wherein the landing gear door is coupled to a landing gear structure of an aircraft. ### Claim 9 A landing gear noise reducing system, the system comprising: a landing gear door; a leading edge section comprising a leading edge of the landing gear door and deflectable toward a landing gear strut; and a door flap comprising a trailing edge of the landing gear door and deflectable toward the landing gear strut. ### Claim 10 (depends on 9) The system of claim 9, further comprising at least one actuator configured to: deflect the leading edge section toward the landing gear strut; and deflect the door flap toward the landing gear strut. ### Claim 11 (depends on 10) The system of claim 10, wherein at least one actuator comprises: a first actuator configured to deflect the leading edge section toward the landing gear strut; and a second actuator configured to deflect the door flap toward the landing gear strut. ### Claim 12 (depends on 9) The system of claim 9, wherein the door flap is located at a percent of a chord plane of the landing gear door. ### Claim 13 (depends on 9) The system of claim 9, wherein a nominal door flap deflection angle of the door flap is below 30 degrees. ### Claim 14 (depends on 9) The system of claim 9, wherein the landing gear door is coupled to a landing gear structure of an aircraft. ### Claim 15 A method for configuring a quiet landing gear door, the method comprising: configuring a landing gear door to deploy to a landing gear deployed position; coupling a leading edge section to the landing gear door to deflect toward a landing gear strut in the landing gear deployed position; and hinging a door flap to the landing gear door to deflect toward the landing gear strut in the landing gear deployed position. ### Claim 16 (depends on 15) The method of claim 15, further comprising configuring the leading edge section and the door flap to reduce a local flow speed near the landing gear strut and minimize a wake impinging on a pressure side of an aerodynamic surface of an aircraft such that a landing gear noise and a landing gear wake-aerodynamic surface interaction noise are reduced. ### Claim 17 (depends on 15) The method of claim 15, further comprising configuring the leading edge section in the leading edge section deployed position and the door flap in the door flap deployed position to reduce a flow velocity on a pressure side of the landing gear door reducing a landing gear wake-wing flap interaction noise. ### Claim 18 (depends on 15) The method of claim 15, further comprising configuring the door flap to deflect below 30 degrees. ### Claim 19 (depends on 15) The method of claim 15, further comprising locating the door flap at a percent chord plane of the landing gear door. ### Claim 20 (depends on 15) The method of claim 15, further comprising coupling the landing gear door to a main landing gear structure of an aircraft.