# US 8,740,139 B1 · Leading edge snag for exposed propeller engine installation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,740,139 B1 - Document ID: US8740139B1 - Status: Granted - Kind: B1 - Application number: 13/453,218 - Filed: 2012-04-23 - Granted: 2014-06-03 - Earliest claimed: 2012-04-23 - Assignees: The Boeing Company - Applicants: Marcus A. Dunavan - Inventors: Marcus A. Dunavan - Web page: https://patentgrep.com/patent/US8740139B1 ## CPC - B64D 27/12: within, or attached to, wings - B64C 3/10: Shape of wings - B64D 2027/005: {Aircraft with an unducted turbofan comprising contra-rotating rotors, e.g. contra-rotating open rotors [CROR]} - Y02T 50/10: Drag reduction - Y02T 50/40: Weight reduction - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - B64C: AEROPLANES; HELICOPTERS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An airplane powered by exposed propeller engines has a swept wing configuration comprising a leading edge snag coincident with the exposed propeller engine mount. The portion of the leading edge disposed inboard of the exposed propeller engine is offset in an aftwise direction relative to the outboard portion of the leading edge. As a result of this construction, the point of closest approach of the blades of the exposed propeller engines is moved aft, allowing for a more compact engine installation. ## Claims ### Claim 1 An aircraft comprising a fuselage, a swept airfoil-shaped body projecting from said fuselage, an exposed propeller engine mounted to said airfoil-shaped body, and a strut that connects said exposed propeller engine to said airfoil-shaped body, wherein said airfoil-shaped body comprises a leading edge comprising a snag coincident with a mounting location of said exposed propeller engine and buried inside said strut, an inboard spanwise portion disposed between said fuselage and said exposed propeller engine, and an outboard spanwise portion disposed between said exposed propeller engine and a tip of said airfoil-shaped body, said inboard spanwise portion being offset in an aftwise direction relative to said outboard spanwise portion. ### Claim 2 (depends on 1) The aircraft as recited in claim 1, wherein said airfoil-shaped body is a wing. ### Claim 3 (depends on 1) The aircraft as recited in claim 1, wherein said airfoil-shaped body is a tail. ### Claim 4 (depends on 1) The aircraft as recited in claim 1, wherein said inboard spanwise portion of said leading edge has a sweep angle greater than a sweep angle of a major portion of said outboard spanwise portion of said leading edge. ### Claim 5 (depends on 4) The aircraft as recited in claim 4, wherein a minor portion of said outboard spanwise portion of said leading edge has a sweep angle greater than said sweep angle of said inboard spanwise portion of said leading edge. ### Claim 6 An aircraft comprising a fuselage, a wingbox that is attached to said fuselage, left and right wing panels supported by said wingbox, first and second exposed propeller engines respectively mounted to said left and right wing panels, and a respective strut that connects a respective exposed propeller engine to a respective one of said left and right wing panels, wherein each of said left and right wing panels comprises upper and lower surfaces and swept leading and trailing edges, each leading edge comprising an inboard spanwise portion disposed between said fuselage and the exposed propeller engine mounted thereto, an outboard spanwise portion disposed between the exposed propeller engine mounted thereto and a tip of the wing panel, and a snag that connects said inboard and outboard spanwise portions at the location of the exposed propeller engine mounted thereto and is buried inside a respective strut, said inboard spanwise portion being offset in an aftwise direction relative to said outboard spanwise portion. ### Claim 7 (depends on 6) The aircraft as recited in claim 6, wherein the inboard spanwise portion of each leading edge has a sweep angle greater than a sweep angle of a major portion of the outboard spanwise portion of the same leading edge. ### Claim 8 (depends on 7) The aircraft as recited in claim 7, wherein a minor portion of the outboard spanwise portion of each leading edge has a sweep angle greater than said sweep angle of the inboard spanwise portion of the same leading edge. ### Claim 9 An aircraft comprising a fuselage, a swept airfoil-shaped body projecting from said fuselage, an exposed propeller engine mounted to said airfoil-shaped body, and a slipper nacelle that connects said exposed propeller engine to said airfoil-shaped body, wherein said airfoil-shaped body comprises a leading edge comprising a snag coincident with a mounting location of said exposed propeller engine and buried inside slipper nacelle, an inboard spanwise portion disposed between said fuselage and said exposed propeller engine, and an outboard spanwise portion disposed between said exposed propeller engine and a tip of said airfoil-shaped body, said inboard spanwise portion being offset in an aftwise direction relative to said outboard spanwise portion. ### Claim 10 An aircraft comprising a fuselage, a wingbox that is attached to said fuselage, left and right wing panels supported by said wingbox, first and second exposed propeller engines respectively mounted to said left and right wing panels, and a respective slipper nacelle that surrounds a respective exposed propeller engine, wherein each of said left and right wing panels comprises upper and lower surfaces and swept leading and trailing edges, each leading edge comprising an inboard spanwise portion disposed between said fuselage and the exposed propeller engine mounted thereto, an outboard spanwise portion disposed between the exposed propeller engine mounted thereto and a tip of the wing panel, and a snag that connects said inboard and outboard spanwise portions at the location of the exposed propeller engine mounted thereto and is buried inside a respective slipper nacelle, said inboard spanwise portion being offset in an aftwise direction relative to said outboard spanwise portion.