# US 11,897,596 B2 · Methods and apparatus for automatically extending aircraft wing flaps in response to detecting an excess energy steep descent condition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,897,596 B2 - Document ID: US11897596B2 - Status: Granted - Kind: B2 - Application number: 17/357,377 - Filed: 2021-06-24 - Published: 2022-01-27 - Granted: 2024-02-13 - Earliest claimed: 2020-07-21 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Sherwin C. Li - Web page: https://patentgrep.com/patent/US11897596B2 ## CPC - B64C 13/16: actuated automatically, e.g. responsive to gust detectors - B64C 9/323: {associated with wings} - G05D 1/0066: {for limitation of acceleration or stress} - G05D 1/0607: {specially adapted for aircraft} - G05D 1/617: Safety or protection, e.g. defining protection zones around obstacles or avoiding hazards (arrangements for controlling the position or course of two or more vehicles for avoiding collisions therebetween G05D1/693; arrangements for reacting to or preventing system or operator failure G05D1/80) - G05D 1/65: Following a desired speed profile - B64C: AEROPLANES; HELICOPTERS - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES ## Abstract Methods and apparatus for automatically extending aircraft wing flaps in response to detecting an excess energy steep descent condition are described. An example control system of an aircraft includes one or more processors. The one or more processors determine whether the aircraft is experiencing an excess energy steep descent (EESD) condition. In response to determining that the aircraft is experiencing the EESD condition, the one or more processors command an actuator of the aircraft coupled to a flap of the aircraft to extend the flap from a current flap position to a subsequent flap position defined by a flap extension sequence. ## Claims ### Claim 1 A control system of an aircraft, the control system comprising: non-transitory machine-readable instructions; and one or more processors to execute the machine-readable instructions to: determine whether the aircraft is experiencing an excess energy steep descent (EESD) condition, the EESD condition corresponding to a flight path angle that meets or exceeds an angular threshold when engines of the aircraft are operating at idle thrust, wherein the angular threshold varies based on a speed of the aircraft; and in response to determining that the aircraft is experiencing the EESD condition, command an actuator of the aircraft coupled to a flap of the aircraft to extend the flap from a current flap position to a subsequent flap position defined by a flap extension sequence. ### Claim 2 (depends on 1) The control system of claim 1, wherein the flap extension sequence includes predetermined successive flap extension positions between a stowed position of the flap and a fully-extended position of the flap, the flap being successively extendible to respective ones of the predetermined successive flap extension positions via the actuator. ### Claim 3 (depends on 1) The control system of claim 1, wherein the speed of the aircraft is to decrease in response to the one or more processors commanding the actuator to extend the flap from the current flap position to the subsequent flap position. ### Claim 4 (depends on 1) The control system of claim 1, wherein the one or more processors are to determine a gamma value of the aircraft based on the speed of the aircraft, and wherein the one or more processors are to determine whether the aircraft is experiencing the EESD condition based on the gamma value and further based on a throttle position of a throttle lever of the aircraft. ### Claim 5 (depends on 4) The control system of claim 4, wherein the gamma value corresponds to the flight path angle of the aircraft. ### Claim 6 (depends on 4) The control system of claim 4, wherein the one or more processors are to detect an occurrence of the EESD condition in response to the gamma value exceeding a gamma value threshold while the throttle position corresponds to an idle thrust position of the throttle lever. ### Claim 7 (depends on 6) The control system of claim 6, wherein the gamma value threshold varies based on the current flap position of the flap in relation to the flap extension sequence. ### Claim 8 A method, comprising: determining, by executing one or more non-transitory machine-readable instructions with one or more processors of a control system of an aircraft, whether the aircraft is experiencing an excess energy steep descent (EESD) condition, the EESD condition corresponding to a flight path angle that meets or exceeds an angular threshold when engines of the aircraft are operating at idle thrust, wherein the angular threshold varies based on a speed of the aircraft; and in response to determining that the aircraft is experiencing the EESD condition, commanding, by executing one or more non-transitory machine-readable instructions with the one or more processors, an actuator of the aircraft coupled to a flap of the aircraft to extend the flap from a current flap position to a subsequent flap position defined by a flap extension sequence. ### Claim 9 (depends on 8) The method of claim 8, wherein the flap extension sequence includes predetermined successive flap extension positions between a stowed position of the flap and a fully-extended position of the flap, the flap being successively extendible to respective ones of the predetermined successive flap extension positions via the actuator. ### Claim 10 (depends on 8) The method of claim 8, wherein the speed of the aircraft decreases in response to the actuator extending the flap from the current flap position to the subsequent flap position. ### Claim 11 (depends on 8) The method of claim 8, further comprising determining, by executing one or more non-transitory machine-readable instructions with the one or more processors, a gamma value of the aircraft based on the speed of the aircraft, wherein determining whether the aircraft is experiencing the EESD condition is based on the gamma value and further based on a throttle position of a throttle lever of the aircraft. ### Claim 12 (depends on 11) The method of claim 11, wherein the gamma value corresponds to the flight path angle of the aircraft. ### Claim 13 (depends on 11) The method of claim 11, wherein an occurrence of the EESD condition is detected in response to the gamma value exceeding a gamma value threshold while the throttle position corresponds to an idle thrust position of the throttle lever. ### Claim 14 (depends on 13) The method of claim 13, wherein the gamma value threshold varies based on the current flap position of the flap in relation to the flap extension sequence. ### Claim 15 A computer program product, comprising a computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to be executed to implement a method of automatically extending aircraft wing flaps, the method comprising: determining whether an aircraft is experiencing an excess energy steep descent (EESD) condition, the EESD condition corresponding to a flight path angle that meets or exceeds an angular threshold when engines of the aircraft are operating at idle thrust, wherein the angular threshold varies based on a speed of the aircraft; and in response to determining that the aircraft is experiencing the EESD condition, commanding an actuator of the aircraft coupled to a flap of the aircraft to extend the flap from a current flap position to a subsequent flap position defined by a flap extension sequence. ### Claim 16 (depends on 15) The computer program product of claim 15, wherein the flap extension sequence includes predetermined successive flap extension positions between a stowed position of the flap and a fully-extended position of the flap, the flap being successively extendible to respective ones of the predetermined successive flap extension positions via the actuator. ### Claim 17 (depends on 15) The computer program product of claim 15, wherein the method further comprises determining a gamma value of the aircraft based on a ground speed of the aircraft and a vertical speed of the aircraft, and wherein determining whether the aircraft is experiencing the EESD condition is based on the gamma value and further based on a throttle position of a throttle lever of the aircraft. ### Claim 18 (depends on 17) The computer program product of claim 17, wherein the gamma value corresponds to the flight path angle of the aircraft. ### Claim 19 (depends on 17) The computer program product of claim 17, wherein an occurrence of the EESD condition is detected in response to the gamma value exceeding a gamma value threshold while the throttle position corresponds to an idle thrust position of the throttle lever. ### Claim 20 (depends on 19) The computer program product of claim 19, wherein the gamma value threshold varies based on the current flap position of the flap in relation to the flap extension sequence.