System and method for determining aircraft hard landing events from inertial and aircraft reference frame data
This invention allows for the precise determination of an aircraft's landing conditions and whether an aircraft has experienced a hard landing that exceeds the allowable design loads of the aircraft's landing gear. The system comprises a computer that measures signals from an inertial measurement unit (IMU) at high data rates (e.g. 100 Hz) and also records signals from the aircraft avionics data bus. The computer compares the output from the inertial measurement unit's accelerometers against at least one predetermined threshold parameter to determine whether the aircraft's three dimensional landing deceleration is safely within the design allowances or other regulatory limitations, or whether the landing event needs further investigation.
1. An apparatus for determining an aircraft hard landing event comprising: a housing mountable in an aircraft having at least one connector allowing interface between the housing and the aircraft power and optionally the aircraft avionics systems; an inertial measurement unit located within the housing; processing means coupled to the inertial measurement unit for receiving data at high data rates therefrom, the processing means including data correlating to at least one threshold parameter for comparison with the data received from the inertial measurement unit to identify when a hard landing has occurred; and an indicator coupled to the housing and connected to the processor for indicating the occurrence of a hard landing, wherein the processing means includes an active recording mode and a passive monitoring mode, the active recording mode being initiated by a predetermined recording event and comprising the receiving and storing of data from the inertial measurement unit and the aircraft avionics system until a predetermined landing event initiates the passive monitoring mode which comprises the processor performing at least one self check.
2. The apparatus according to claim 1 , further comprising an avionic bus interface circuit located within the housing and adapted to couple to the aircraft avionics system and receive and process data therefrom.
3. The apparatus according to claim 1 , wherein the processing means is additionally coupled to the avionic bus interface circuit for receiving data therefrom.
4. The apparatus according to claim 1 , further comprising a removable memory card for storing data thereon.
5. The apparatus according to claims 1 , wherein the indicator is selected from an incandescent indicator and a magnetic latching indicator.
6. The apparatus according to claim 1 , wherein the indicator is located on an external surface of the housing.
7. An apparatus for determining an aircraft hard landing event comprising: a housing mountable in an aircraft having at least one connector allowing interface between the housing and the aircraft power and optionally the aircraft avionics systems; a plurality of acceleration sensors; a plurality of gyroscopes selected from the group consisting of angle sensors and angular rate sensors; processing means coupled to the sensors and the gyroscopes for receiving data therefrom, the processing means including data correlating to at least one threshold parameter for comparison with the data received from the sensors and the gyroscopes to identify when a hard landing has occurred; and an indicator coupled to the housing and connected to the processor for indicating the occurrence of a hard landing, wherein the processing means includes an active recording mode and a passive monitoring mode, the active recording mode being initiated by a predetermined recording event and comprising the receiving and storing of data from the inertial measurement unit and the aircraft avionics system until a predetermined landing event initiates the passive monitoring mode which comprises the processor performing at least one self check.
8. The apparatus according to claim 7 , further comprising an avionic bus interface circuit located within the housing and adapted to couple to the aircraft avionics system and receive and process data therefrom.
9. The apparatus according to claim 7 , wherein the processing means is additionally coupled to the avionic bus interface circuit for receiving data therefrom.
10. The apparatus according to claims 7 , further comprising a removable memory card for storing data thereon.
11. The apparatus according to claim 7 , wherein the indicator is selected from an incandescent indicator and a magnetic latching indicator.
12. The apparatus according to claim 7 , wherein the indicator is located on an external surface of the housing.