Method of protecting an aircraft landing gear while the aircraft is being towed, and pin for coupling a towing bar to an orientable lower part of a landing gear
View Patent ↗A method of protecting an aircraft undercarriage ( 1 ) while it is being towed by means of a tow bar ( 13 ) hitched to a steerable bottom portion of the undercarriage, the method including the step of generating an alarm when a towing force imposed by the tow bar on the undercarriage reaches or exceeds a predetermined force threshold. The threshold is caused to vary as a function of an orientation of the steerable bottom portion of the undercarriage.
1. A pin for coupling a tow bar to a steerable bottom portion of an undercarriage having a pivot axis that is inclined relative to the vertical, wherein the pin comprises:
means for measuring the forces to which the pin is subjected;
means for measuring the angle of inclination of the pin relative to the horizontal;
means for calculating a force threshold as a function of the orientation of the bottom portion of the undercarriage as deduced from the angle of inclination of the pin; and
means for comparing a measured force with the force threshold and for generating an alarm if the measured forces reach or exceed a force threshold.
2. A pin according to claim 1 , wherein the means for measuring the angle of inclination of the pin relative to the horizontal comprise an accelerometer.
3. A method of protecting an aircraft undercarriage having a pivot axis that is inclined relative to the vertical, while the undercarriage is being towed by means of a tow bar hitched to the steerable bottom portion of the undercarriage, the method including the step of using a pin according to claim 1 in order to generate an alarm when a towing force imposed by the tow bar on the undercarriage reaches or exceeds a predetermined force threshold.
4. A method according to claim 3 , wherein said threshold is caused to vary as a function of the orientation of the steerable bottom portion of the undercarriage.
5. A method according to claim 3 , wherein the alarm is an alphanumeric display or an audible and/or visible warning.
6. A pin according to claim 2 , wherein the accelerometer is a three-axis accelerometer.
7. A method of protecting an aircraft undercarriage having a pivot axis that is inclined relative to the vertical, while the undercarriage is being towed by means of a tow bar hitched to the steerable bottom portion of the undercarriage, the method including the step of using a pin according to claim 2 in order to generate an alarm when a towing force imposed by the tow bar on the undercarriage reaches or exceeds a predetermined force threshold.
8. A method of protecting an aircraft undercarriage having a pivot axis that is inclined relative to the vertical, while the undercarriage is being towed by means of a tow bar hitched to the steerable bottom portion of the undercarriage, the method including the step of using a pin according to claim 6 in order to generate an alarm when a towing force imposed by the tow bar on the undercarriage reaches or exceeds a predetermined force threshold.
9. A method according to claim 7 , wherein said threshold is caused to vary as a function of the orientation of the steerable bottom portion of the undercarriage.
10. A method according to claim 8 , wherein said threshold is caused to vary as a function of the orientation of the steerable bottom portion of the undercarriage.
11. A method according to claim 7 , wherein the alarm is an alphanumeric display or an audible and/or visible warning.
12. A method according to claim 8 , wherein the alarm is an alphanumeric display or an audible and/or visible warning.