Aircraft landing gear monitoring apparatus
View Patent ↗An apparatus is disclosed for monitoring the load on at least one part of an aircraft landing gear during landing of the aircraft. The apparatus comprises a housing containing a sensor which senses a parameter indicative of the load in the part of the landing gear, a processor which receives signals from the sensor and processes the signals to produce data representative of the parameter measured by the sensor, a battery which provides electrical power to the processor, a memory for storing measurement data from the processor, and a wireless transmitter which is controlled by the processor. The wireless transmitter is arranged to transmit at least some of the measurement data from the processor to a remote device located outside of the housing.
1. A method for monitoring the load on at least one part of an aircraft landing gear during landing of the aircraft, said method comprising the steps of:
monitoring output from a landing gear deployment sensor for a first indication indicating that the landing gear of the aircraft has been deployed;
obtaining strain measurements from one or more parts of said landing gear in response to said first indication until one or more of said strain measurements exceeds a first predetermined strain threshold indicating a landing event having occurred;
storing data representing the peak strain measurement if said peak strain measurement exceeds a second predetermined strain threshold indicating that said landing event represented a hard landing;
enabling a wireless transmitter in response to said storing of said peak strain measurement data for transmitting said peak strain measurement data from said aircraft to an external device, wherein powering up of a measurement device is delayed for a first predetermined period after said first indication from said landing gear deployment sensor, and wherein said predetermined period is set so as to conserve power before said landing; and,
determining whether a landing has occurred when the strain has exceeded the first pre-determined threshold; based on said determining, wherein said transmitter is disabled after a second predetermined period after said landing event, and stopping said sampling after a first delay if said landing has occurred, or said transmitter is disabled in response to a detection of a second indication from said landing gear deployment sensor indicating that said landing gear has been stowed, and stopping said sampling after a second delay if said landing has not occurred, wherein said second delay is longer than said first delay.
2. A method according to claim 1 in which said peak strain measurement data is transmitted in response to a request signal from said external device.
3. A method according to claim 1 in which peak strain measurement data representing a predetermined set of hard landings is stored.
4. A method according to claim 1 in which said peak strain measurement data is associated with a corresponding time stamp.
5. A method according to claim 1 in which said peak strain measurement data is provided in the form of an indication that said output of said strain measurement device has exceeded said second predetermined strain threshold.
6. An apparatus for monitoring the load on at least one part of an aircraft landing gear during landing of the aircraft, said apparatus being operable to:
monitor output from a landing gear deployment sensor for a first indication indicating that the landing gear of the aircraft has been deployed;
obtain strain measurements from one or more parts of said landing gear in response to said first indication until one or more of said strain measurements exceeds a first predetermined strain threshold indicating a landing event having occurred;
store data representing the peak strain measurement if said peak strain measurement exceeds a second predetermined strain threshold indicating that said landing event represented a hard landing;
enable a wireless transmitter in response to said storing of said peak strain measurement data for transmitting said peak strain measurement data from said aircraft to an external device, wherein powering up of a strain measurement device is delayed for a first predetermined period after said first indication from said landing gear deployment sensor, and wherein said predetermined period is set so as to conserve power before said landing; and,
determining whether a landing has occurred when the strain has exceeded the first pre-determined threshold; based on said determining, said transmission means is disabled after a second predetermined period after said landing event, and stopping said sampling after a first delay if said landing has occurred, or said transmission means is disabled in response to a detection of a second indication from said landing gear deployment sensor indicating that said landing gear has been stowed and stopping said sampling after a second delay if said landing has not occurred, wherein said second delay is longer than said first delay.
7. An apparatus according to claim 6 in which said peak strain measurement data is transmitted in response to a request signal from said external device.
8. An apparatus according to claim 6 in which peak strain measurement data representing a predetermined set of hard landings is stored.
9. An apparatus according to claim 6 in which said peak strain measurement data is associated with a corresponding time stamp.
10. An apparatus according to claim 6 in which said peak strain measurement data is provided in the form of an indication that said output of said strain measurement device has exceeded said second predetermined strain threshold.