# US 12,759,727 B2 · Electrical lockout system for aircraft propulsion system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,727 B2 - Document ID: US12759727B2 - Status: Granted - Kind: B2 - Application number: 18/920,227 - Filed: 2024-10-18 - Published: 2026-04-23 - Granted: 2026-10-13 - Earliest claimed: 2024-10-18 - Assignees: Rtx Corporation - Applicants: RTX Corporation - Inventors: Thomas E. Clark; Murat Yazici; John Akin; Andrew E. Breault; Jeffrey T. Morton - Web page: https://patentgrep.com/patent/US12759727B2 ## CPC - B64D 45/00: Aircraft indicators or protectors not otherwise provided for - B64D 29/06: Attaching of nacelles, fairings or cowlings - B64D 2221/00: Electric power distribution systems onboard aircraft - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT ## Abstract A propulsion system for an aircraft includes a propulsor rotor, a powerplant, a nacelle and a lockout system. The powerplant is coupled to and configured to drive rotation of the propulsor rotor. An electrical system for the powerplant is configured to receive electrical power from an electrical power source. The nacelle includes an access structure configured to move between a first position and a second position. The access structure at least partially covers the electrical system when in the first position. The access structure is arranged in the first position for propulsion system operation. The access structure is operable to be arranged in the second position for propulsion system maintenance and/or propulsion system inspection. The lockout system is configured to automatically trigger an operation to cut off the electrical power to the electrical system from the electrical power source when the access structure moves away from the first position. ## Claims ### Claim 1 A propulsion system for an aircraft, comprising: a propulsor rotor; a powerplant coupled to and configured to drive rotation of the propulsor rotor, an electrical system for the powerplant configured to receive electrical power from an electrical power source, the electrical system comprising a plurality of electrical components mounted to or integrated with the propulsion system;; a nacelle comprising an access structure configured to move between a first position and a second position, the access structure obstructs access to the plurality of electrical components when in the first position, and un-obstructs access to the plurality of electrical components when in the second position; one or more switches electrically coupled between the electrical power source and the electrical system and configured to electrically couple the electrical power source to the electrical system during propulsion system operation; and a lockout system configured to automatically trigger opening of the one or more switches to electrically decouple the electrical power source from the electrical system in response to movement of the access structure away from the first position, wherein the opening of the one or more switches de-energizes the plurality of electrical components. ### Claim 2 (depends on 1) The propulsion system of claim 1, wherein the lockout system is configured to automatically trigger the operation to cut off the electrical power to the electrical system from the electrical power source when the access structure is out of the first position. ### Claim 3 (depends on 1) The propulsion system of claim 1, further comprising: a controller, the lockout system configured to provide a lockout signal to the controller when the access structure moves away from the first position, and the controller configured to control operation of the one or more switches such that the one or more switches open in response to the controller receiving the lockout signal. ### Claim 4 (depends on 1) The propulsion system of claim 1, further comprising a user interface configured to provide a notification in response to the lockout system cutting off the electrical power to the electrical system from the electrical power source. ### Claim 5 (depends on 1) The propulsion system of claim 1, further comprising: a memory; and a processing device configured to log an entry in the memory in response to the lockout system cutting off the electrical power to the electrical system from the electrical power source. ### Claim 6 (depends on 1) The propulsion system of claim 1, wherein the electrical system comprises an electric machine. ### Claim 7 (depends on 1) The propulsion system of claim 1, wherein the electrical system comprises a controller. ### Claim 8 (depends on 1) The propulsion system of claim 1, wherein the electrical power source comprises a battery system onboard the aircraft. ### Claim 9 (depends on 1) The propulsion system of claim 1, wherein the electrical power source comprises an electrical power bus onboard the aircraft. ### Claim 10 (depends on 1) The propulsion system of claim 1, wherein the powerplant comprises a thermal engine. ### Claim 11 (depends on 1) The propulsion system of claim 1, wherein the access structure comprises a cowl door. ### Claim 12 (depends on 1) The propulsion system of claim 1, wherein the access structure comprises a thrust reverser half. ### Claim 13 (depends on 1) The propulsion system of claim 1, wherein the access structure comprises an access panel. ### Claim 14 (depends on 1) The propulsion system of claim 1, wherein the lockout system comprises a latch sensor configured to sense when a latch for the access structure is unlatched; and the lockout system is configured to automatically trigger the operation to cut off the electrical power to the electrical system from the electrical power source when the latch sensor senses the latch is unlatched. ### Claim 15 (depends on 1) The propulsion system of claim 1, wherein the lockout system comprises a proximity sensor configured to sense when the access structure moves from the first position; and the lockout system is configured to automatically trigger the operation to cut off the electrical power to the electrical system from the electrical power source when the proximity sensor senses the access structure moving from the first position. ### Claim 16 (depends on 1) The propulsion system of claim 1, wherein the lockout system comprises a hinge sensor disposed at a hinge connecting the access structure to another structure of the propulsion system; and the lockout system is configured to automatically trigger the operation to cut off the electrical power to the electrical system from the electrical power source when the hinge sensor senses movement in the hinge. ### Claim 17 (depends on 1) The propulsion system of claim 1, further comprising an override configured to override the lockout system and electrically couple the electrical power source to the electrical system. ### Claim 18 A propulsion system for an aircraft, comprising: a turbine engine including a compressor section, a combustor section and a turbine section; an electrical system comprising a plurality of electrical components arranged with the turbine engine, the electrical system configured to receive electrical power from an electrical power source onboard the aircraft; a housing structure at least partially surrounding the turbine engine, the housing structure comprising an access structure covering a portion of the turbine engine with access to the electrical system, and the access structure configured in a first position for propulsion system operation, wherein the access structure is configured to be moved from the first position for propulsion system maintenance and/or propulsion system inspection; and a lockout system configured to trigger electric decoupling of the electrical power source from the electrical system when the access structure moves away from the first position to uncover th portion of the turbine engine with access to the electrical system. ### Claim 19 An open rotor propulsion system for an aircraft, comprising: a turbine engine including a compressor section, a combustor section and a turbine section; an electrical system comprising an electrical component arranged with the turbine engine, the electrical system configured to direct electrical power from an electrical power source onboard the aircraft to the electrical component at least during propulsion system operation; a housing structure at least partially housing the turbine engine, the housing structure comprising an access structure covering a portion of the turbine engine with access to the electrical system, and the access structure configured in a first position for the propulsion system operation, wherein the access structure is configured to be moved from the first position for propulsion system maintenance and/or propulsion system inspection; one or more switches electrically coupled between the electrical power source and the electrical system and configured to electrically couple the electrical power source to the electrical system during operation of the open rotor propulsion system; and a lockout system configured to open the one or more switches to electrically decouple the electrical power source from the electrical system when the access structure is disposed out of the first position to uncover the portion of the turbine engine with access to the electrical system.