# US 11,305,894 B2 · Detection of fan case liner damage during turbine engine operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,305,894 B2 - Document ID: US11305894B2 - Status: Granted - Kind: B2 - Application number: 16/697,929 - Filed: 2019-11-27 - Published: 2020-06-04 - Granted: 2022-04-19 - Earliest claimed: 2018-11-30 - Assignees: Gulfstream Aerospace Corporation - Applicants: Gulfstream Aerospace Corporation - Inventors: Vincent DeChellis; Mike Lucas; Tongan Wang; Nicholas Ward; Paul Conti - Web page: https://patentgrep.com/patent/US11305894B2 ## CPC - B64F 5/60: Testing or inspecting aircraft components or systems - F01D 17/02: Arrangement of sensing elements - B64D 45/00: Aircraft indicators or protectors not otherwise provided for - F01D 21/003: {Arrangements for testing or measuring (for measuring vibrations G01H)} - G01M 15/14: Testing gas-turbine engines or jet-propulsion engines - B64D 2045/0085: {Devices for aircraft health monitoring, e.g. monitoring flutter or vibration} - F05D 2260/80: Diagnostics - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - 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 - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An aircraft includes a turbine engine, a vibration sensor, and a processor. The vibration sensor is attached to the turbine engine and is configured to output a vibration sensor signal. The processor is programmed to determine whether the vibration sensor signal indicates that fan case liner damage has occurred due to icing conditions. The processor is further programmed to indicate that a fan case inspection should be conducted in response to the vibration sensor signal indicating that fan case liner damage has occurred. ## Claims ### Claim 1 An aircraft, comprising: a turbine engine having a fan case with a fan case liner; a vibration sensor attached to the turbine engine and configured to output a vibration sensor signal that indicates broadband acceleration of the turbine engine; and a processor programmed to: determine whether the broadband acceleration of the turbine engine indicates that damage to the fan case liner has occurred due to icing conditions; and indicate that inspection of the fan case should be conducted in response to the broadband acceleration of the turbine engine indicating that damage to the fan case liner has occurred. ### Claim 2 (depends on 1) The aircraft of claim 1, wherein the processor is further programmed to: extract a broadband vibration value from the vibration sensor signal; and determine that the vibration sensor signal indicates that damage to the fan case liner has occurred in response to the broadband vibration value exceeding a broadband vibration threshold that indicates damage to the fan case liner due to ice shedding in the turbine engine may have occurred. ### Claim 3 (depends on 1) The aircraft of claim 1, wherein the processor is further programmed to: retrieve a rotor rotation frequency of the turbine engine; form a harmonic indicator based on at least one harmonic frequency of the rotor rotation frequency; and determine that the vibration sensor signal indicates that damage to the fan case liner has occurred in response to the harmonic indicator exceeding a harmonic threshold that indicates damage to the fan case liner may have occurred due to an unbalanced rotor in the turbine engine. ### Claim 4 (depends on 3) The aircraft of claim 3, wherein the processor is further programmed to form the harmonic indicator using at least two higher order harmonic frequencies. ### Claim 5 (depends on 4) The aircraft of claim 4, wherein the processor is further programmed to form the harmonic indicator as an aggregate magnitude of the at least two higher order harmonic frequencies. ### Claim 6 (depends on 1) The aircraft of claim 1, wherein the processor is further configured to indicate that no damage has occurred to the turbine engine when the vibration sensor signal indicates that a broadband vibration value and harmonic frequencies of the turbine engine do not exceed damage indicator thresholds. ### Claim 7 (depends on 1) The aircraft of claim 1, wherein the processor is an engine controller on the aircraft. ### Claim 8 (depends on 1) The aircraft of claim 1, wherein the processor is a component of an external device that is configured to communicate with the vibration sensor to receive the vibration sensor signal during operation of the turbine engine. ### Claim 9 (depends on 8) The aircraft of claim 8, wherein the processor is further programmed to receive an input indicating a model of the aircraft and to determine whether the vibration sensor signal indicates that fan case liner damage has occurred based on the model of the aircraft. ### Claim 10 A device for damage monitoring of a turbine engine having a fan case with a fan case liner, the device comprising: an input port configured to receive a vibration sensor signal from a vibration sensor attached to the turbine engine, the vibration sensor signal indicating broadband acceleration of the turbine engine; and a processor programmed to: determine whether the broadband acceleration of the turbine engine indicates that damage to the fan case liner has occurred in the turbine engine due to icing conditions; and indicate that inspection of the fan case should be conducted in response to the broadband acceleration of the turbine engine indicating that damage to the fan case liner has occurred. ### Claim 11 (depends on 10) The device of claim 10, wherein the processor is further programmed to: extract a broadband vibration value from the vibration sensor signal; and determine that the vibration sensor signal indicates that damage to the fan case liner has occurred in response to the broadband vibration value exceeding a broadband vibration threshold that indicates damage to the fan case liner due to ice shedding in the turbine engine may have occurred. ### Claim 12 (depends on 10) The device of claim 10, wherein the processor is further programmed to: retrieve a rotor rotation frequency of the turbine engine; form a harmonic indicator based on at least one harmonic frequency of the rotor rotation frequency; and determine that the vibration sensor signal indicates that damage to the fan case liner has occurred in response to the harmonic indicator exceeding a harmonic threshold that indicates damage to the fan case liner may have occurred due to an unbalanced rotor in the turbine engine. ### Claim 13 (depends on 12) The device of claim 12, wherein the processor is further programmed to form the harmonic indicator using at least two higher order harmonic frequencies. ### Claim 14 (depends on 13) The device of claim 13, wherein the processor is further programmed to form the harmonic indicator as an aggregate magnitude of the at least two higher order harmonic frequencies. ### Claim 15 (depends on 10) The device of claim 10, wherein the processor is further configured indicate that no damage has occurred to the turbine engine when the vibration sensor signal indicates that a broadband vibration value and harmonic frequencies of the turbine engine do not exceed damage indicator thresholds. ### Claim 16 (depends on 10) The device of claim 10, wherein the device is external to the turbine engine and an aircraft on which the turbine engine is installed and is configured to communicate with the vibration sensor to receive the vibration sensor signal during operation of the turbine engine. ### Claim 17 (depends on 16) The device of claim 16, wherein the processor is further programmed to receive an input indicating a model of the aircraft and to determine whether the vibration sensor signal indicates that fan case liner damage has occurred based on the model of the aircraft. ### Claim 18 A device for damage monitoring of a turbine engine having a fan case with a fan case liner, the device comprising: at least one non-transitory computer readable storage device having executable instructions stored thereon; and at least one processor associated with the at least one non-transitory computer readable storage device, wherein the executable instructions are configurable to cause the at least one processor to perform a method comprising the steps of: receiving a vibration sensor signal provided by an accelerometer attached to the turbine engine, the vibration sensor signal indicating broadband acceleration of the turbine engine during operation; retrieving a rotor rotation frequency of the turbine engine; forming a harmonic indicator based on at least one harmonic frequency of the rotor rotation frequency; extracting, from the vibration sensor signal, a vibration amplitude at the at least one harmonic frequency; and generating a potential engine damage alert based on characteristics of the harmonic indicator and the vibration amplitude.