System for monitoring damage to a rotor blade of a rotary-wing aircraft

A rotary-wing aircraft rotor blade, comprising:

• a skin and a composite structure with fibers that define leading and trailing edges, a longitudinal axis, and a root zone opposite a free end of the blade;
• and
• a damage monitoring system comprising,
• under said skin, first and second arrays of loops that each has electrical continuity in the absence of damage to the blade, said first and second arrays overlapping and being separated from each other by an insulating material, wherein loops of said first array extend along respective axes that are oblique to said longitudinal axis and loops of said second array extend along respective axes that are substantially perpendicular to the axes of said first array, and
• under said skin in a vicinity of said root zone, an integrated unit that is connected to said loops of said first and second arrays by conductors that are grouped together in a bundle extending longitudinally inside the blade near said leading edge, said integrated unit also being connected to convey data from said monitoring system to an aircraft, said integrated unit comprising an impedance measuring and scanning device for repeatedly scanning an impedance of each of said loops of said first and second arrays.