# US 11,027,855 B2 · Systems and methods for monitoring low speed of a rotorcraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,855 B2 - Document ID: US11027855B2 - Status: Granted - Kind: B2 - Application number: 13/585,276 - Filed: 2012-08-14 - Published: 2014-02-20 - Granted: 2021-06-08 - Earliest claimed: 2012-08-14 - Assignees: Honeywell International Inc. - Applicants: Gary A. Ostrum; Yasuo Ishihara; Steve C. Johnson - Inventors: Gary A. Ostrum; Yasuo Ishihara; Steve C. Johnson - Web page: https://patentgrep.com/patent/US11027855B2 ## CPC - B64D 43/02: for indicating aircraft speed or stalling conditions - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT ## Abstract Systems and methods to provide alerts when a rotorcraft is in a low airspeed condition. During takeoff or go-around, an aural alert is provided to the pilot before the aircraft slows to less than the effective translational lift speed. The aural, visual, and/or tactile alert gets the pilot's attention to manage the aircraft's airspeed before it is too late in this critical flight phase. ## Claims ### Claim 1 A method comprising: determining engine torque information with an engine sensor; determining vehicle position and airspeed information of a vehicle with an air data computer; receiving, at a processing device, the engine torque information, the vehicle position, and the airspeed information; determining, at the processing device, if operation intent of vehicle meets at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information, the at least one predefined criterion being a take-off or a go-around condition; if the intent meets the at least one predefined criterion, generating, at the processing device, a first low-speed alert with an output device if airspeed is less than a best rate-of-climb speed (Vbroc) by a threshold amount and an acceleration value based on the airspeed is between a first acceleration value and a second acceleration value; and providing the first low-speed alert to an operator with an output device. ### Claim 2 (depends on 1) The method of claim 1, wherein if the intent meets the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information, generating a second speed alert if the acceleration value is less than the second acceleration value; and providing the second low-speed alert to an operator with the output device. ### Claim 3 (depends on 1) The method of claim 1, further comprising at the processing device, receiving autopilot status information; and determining if operation intent of vehicle meets at least one predefined criterion, further based on the received autopilot status information. ### Claim 4 (depends on 1) The method of claim 1, wherein the providing the first low-speed alert to the operator with the output device includes providing the first low-speed alert to the operator with a display device. ### Claim 5 (depends on 1) The method of claim 1, wherein, if the operation intent of the vehicle fails to meet the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information, then the processing device, without generating the first low-speed alert, continues to receive the engine torque information, the vehicle position, and the airspeed information until the processing device determines that the operation intent of the vehicle meets the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information. ### Claim 6 (depends on 5) The method of claim 5, wherein, if the airspeed is not less than the best rate-of-climb speed (Vbroc) by the threshold amount, or if the acceleration value based on the airspeed is not between the first acceleration value and the second acceleration value, then the processing device, without generating the first low-speed alert, continues to receive the engine torque information, the vehicle position, and the airspeed information until the processing device determines that the operation intent of the vehicle meets the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information, the airspeed is less than the best rate-of-climb speed (Vbroc) by the threshold amount, and the acceleration value based on the airspeed is between the first acceleration value and the second acceleration value. ### Claim 7 A system for monitoring a condition of a rotorcraft, the system located in the rotorcraft, the system comprising: an engine sensor configured to determine engine torque information of an engine of the rotorcraft; an air data computer configured to determine position and airspeed information of the rotorcraft; a processing device configured to receive the engine torque information, the position, and the airspeed information associated with the rotorcraft, the processing device configured to determine, based on the received torque, position, and airspeed information, when the rotorcraft is in a take-off condition or when the rotorcraft is in a go-around condition; the processing device configured to generate a first low-speed alert when the rotorcraft is in the take-off condition or when the rotorcraft is in the go-around condition, and if : (a) airspeed is less than a predetermined speed by a threshold amount and (b) an acceleration value is between a first and second acceleration value, the acceleration value being a rate of change of the airspeed; and an output device configured to present the first low-speed alert to an operator of the rotorcraft. ### Claim 8 (depends on 7) The system of claim 7, wherein the predetermined speed comprises a best rate-of-climb speed (Vbroc). ### Claim 9 (depends on 7) The system of claim 7, the processing device configured to generate a second speed alert if the acceleration value is less than the second acceleration value, when the rotorcraft is in the take-off condition or when the rotorcraft is in the go-around condition, based on the received position and airspeed information, and wherein the output device is further configured to present the second speed alert to the operator of the rotorcraft. ### Claim 10 (depends on 7) The system of claim 7, further comprising: an autopilot system to generate autopilot status information, and wherein the processing device receives the autopilot status information and determines when the rotorcraft is in the take-off condition or when the rotorcraft is in the go-around condition further based on the received autopilot status information. ### Claim 11 A system for monitoring a condition of a vehicle, the system located in the vehicle, the system comprising: a position and speed sensor configured to determine vehicle position and airspeed information; a processing device configured to determine if operation intent of the vehicle meets at least one predefined criterion based on the determined vehicle position and airspeed information, operation intent comprising a take-off condition or a go-around condition; and if the operation intent meets the at least one predefined criterion, generate: a first low-speed alert if (a) airspeed is less than a predetermined speed by a threshold amount and (b) an acceleration value based on the airspeed is between a first acceleration value and a second acceleration value; and an output device configured to present the first low-speed alert to an operator of the vehicle. ### Claim 12 (depends on 11) The system of claim 11, wherein the predetermined speed comprises a best rate-of-climb speed (Vbroc). ### Claim 13 (depends on 11) The system of claim 11, wherein the processing device is further configured to generate a second speed alert if the acceleration value is less than the second acceleration value, if the intent meets the at least one predefined criterion, based on the determined vehicle position and airspeed information. ### Claim 14 (depends on 11) The system of claim 11, further comprising: an autopilot system configured to generate autopilot status information, wherein the processing device is further configured to determine if operation intent of the vehicle meets at least one predefined criterion, further based on the generated autopilot status information. ### Claim 15 (depends on 11) The system of claim 11, further comprising: an engine sensor configured to determine engine torque information; and wherein the processing device is further configured to determine if operation intent of vehicle meets at least one predefined criterion, further based on the determined engine torque information. ### Claim 16 (depends on 15) The system of claim 15, wherein, if the operation intent of the vehicle fails to meet the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information, then the processing device, without generating the first low-speed alert, continues to receive the engine torque information, the vehicle position, and the airspeed information until the processing device determines that the operation intent of the vehicle meets the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information. ### Claim 17 (depends on 16) The system of claim 16, wherein, if the airspeed is not less than the predetermined speed by the threshold amount, or if the acceleration value based on the airspeed is not between the first acceleration and the second acceleration value, then the processing device, without generating the first low-speed alert, continues to receive the engine torque information, the vehicle position, and the airspeed information until the processing device determines that the operation intent of the vehicle meets the at least one predefined criterion based on the received engine torque information, vehicle position, and airspeed information, the airspeed is less than the best rate-of-climb speed (Vbroc) by the threshold amount, and the acceleration value based on the airspeed is between the first acceleration value and the second acceleration value. ### Claim 18 (depends on 11) The system of claim 11, further comprising: an air data computer coupled to the processing device and configured to determine rate-of-altitude change information; and wherein the processing device is further configured to determine if operation intent of vehicle meets at least one predefined criterion further based on the determined rate-of-altitude change information. ### Claim 19 (depends on 11) The system of claim 11, wherein the output device is a display device.