# US 12,180,894 B1 · Electric starter verification during gas-turbine engine barring > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,180,894 B1 - Document ID: US12180894B1 - Status: Granted - Kind: B1 - Application number: 18/360,933 - Filed: 2023-07-28 - Granted: 2024-12-31 - Earliest claimed: 2023-07-28 - Assignees: ROLLS-ROYCE plc; Rolls-Royce North American Technologies Inc. - Applicants: Rolls-Royce Corporation; Rolls-Royce North American Technologies, Inc. - Inventors: Jeffrey Lawrence; Brian Joseph Huber; Erik A. Munevar; Douglas Keith Schetzel, II - Web page: https://patentgrep.com/patent/US12180894B1 ## CPC - F02C 7/268: Starting drives for the rotor {, acting directly on the rotor of the gas turbine to be started} - F01D 19/00: Starting of machines or engines; Regulating, controlling, or safety means in connection therewith (warming-up before starting F01D25/10; turning or inching gear F01D25/34) - F02C 7/26: Starting; Ignition - F02C 7/262: Restarting after flame-out - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F05D 2260/85: Starting - F05D 2270/092: in particular blow-out and relight - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An example system includes a first gas-turbine engine configured to propel an aircraft, the first gas-turbine engine comprising a first electric starter, the first electric starter configured to rotate a spool of the first gas-turbine engine; and one or more controllers collectively configured to: cause, following operation of the first gas-turbine engine, the first electric starter to perform barring of the first gas-turbine engine; measure, during the barring of the first gas-turbine engine, values of one or more parameters of the first gas-turbine engine; and determine, based on the values of the one or more parameters, whether the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine. ## Claims ### Claim 1 A system comprising: a first gas-turbine engine configured to propel an aircraft, the first gas-turbine engine comprising a first electric starter, the first electric starter configured to rotate a spool of the first gas-turbine engine; and one or more controllers collectively configured to: cause, following operation of the first gas-turbine engine, the first electric starter to perform barring of the first gas-turbine engine; measure, during the barring of the first gas-turbine engine, values of one or more parameters of the first gas-turbine engine; and determine, based on the values of the one or more parameters, whether the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine. ### Claim 2 (depends on 1) The system of claim 1, wherein the one or more parameters of the first gas-turbine engine include a rotational speed of the spool of the first gas-turbine engine. ### Claim 3 (depends on 2) The system of claim 2, wherein, to determine whether the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine, the one or more controllers are configured to: responsive to determining that the rotational speed of the spool of the first gas-turbine engine is greater than a threshold rotational speed, determine that the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine. ### Claim 4 (depends on 1) The system of claim 1, wherein the one or more controllers comprise: a motor controller; and an electronic engine controller (EEC). ### Claim 5 (depends on 4) The system of claim 4, wherein, during a shutdown procedure of the EEC, the EEC is configured to transfer control authority over the electric starter to the motor controller, and wherein, responsive to receiving the control authority, the motor controller is configured to cause the first electric starter to perform the barring of the first gas-turbine engine. ### Claim 6 (depends on 5) The system of claim 5, wherein, during the barring, the motor controller is configured to: measure the values of one or more parameters of the first gas-turbine engine; and determine, based on the values of the one or more parameters, whether the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine. ### Claim 7 (depends on 6) The system of claim 6, wherein the motor controller is further configured to determine that the barring is complete and cease causing the first electric starter to perform the barring of the first gas-turbine engine responsive to determining that one or more barring completion criterion have been met. ### Claim 8 (depends on 7) The system of claim 7, wherein, responsive to receiving a control interrupt from the EEC, the motor controller is configured to surrender the control authority over the electric starter to the EEC. ### Claim 9 (depends on 7) The system of claim 7, wherein, responsive to receiving a control interrupt from the EEC, the motor controller is further configured to output an indication of whether the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine. ### Claim 10 (depends on 7) The system of claim 7, wherein the motor controller receives the controller interrupt prior to determining that the one or more barring completion criterion have been met. ### Claim 11 (depends on 1) An airframe comprising the system of claim 1. ### Claim 12 (depends on 1) The system of claim 1, wherein the one or more controllers are collectively configured to: output an indication whether or not the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine. ### Claim 13 (depends on 1) The system of claim 1, wherein the one or more controllers are collectively configured to: perform the mid-air restart of the first gas-turbine engine by at least causing the first electric starter to rotate the spool while fuel is introduced into a combustion chamber of the first gas-turbine engine.