Patent ID: 8532845

Claim:
A method of monitoring the effectiveness of a damper system for damping the movement components of equipment of an aircraft that result from the lead-lag resonant frequency (ω δ ) of said equipment, said damper system including two strength members that are movable relative to each other and that are connected together by a damper member, the method comprising: a) measuring, with a movement sensor, the relative movements of the two strength members; b) filtering, with an electronic filter, the measurements to isolate those that relate to the lead-lag resonant frequency of the equipment; c) rectifying, with an electronic circuit, the signal that results from the filtering; d) recording the rectified signal (S); e) comparing, with a comparator circuit, the rectified signal (S) with a predetermined threshold value (S L ) and returning to step a) so long as the rectified signal (S) does not exceed said threshold value (S L ); f) determining an initial time instant T 0 as soon as the rectified signal exceeds the threshold value (S L ); g) calculating, with an integrator circuit, an integral I 1 of the rectified signal from T 0 to T 0 +δ, where δ is a predetermined time interval characteristic of the damped equipment; h) calculating, with the integrator circuit, an integral I p of the rectified signal from T 0 to T 0 +pδ, where p is an integer equal to 2, 3, 4, or 5; i) calculating a ratio R where R=I p /I 1 ; j) comparing the ratio R with a predetermined limit value R L ; k) returning to step a) if the ratio R is less than the limit value R L ; l) activating and delivering an alert instruction (V 1 ) if the ratio R is greater than or equal to the limit value R L , said alert instruction corresponding to a failure of the damper system; and m) using an electrical power supply to operate at least the filter and the circuits.