A system (2, 12, 22) for evaluating the clogging of an air filter, said air filter equipping an aircraft provided with at least one engine, said air filter being positioned at an air intake, said evaluation system (2, 12, 22) enabling generation of an item of information relative to the clogging of said air filter and including: • a first measuring component (7, 17, 27) performing a measurement of differential pressure Δpt between a reference pressure and a pressure measured upstream of said air filter in said air intake, • a second measuring component (8, 18, 28) enabling determination of a value of the operating power P, Pcor of said at least one engine, and • at least one computer (9, 19, 29) configured to generate said information under the dependence of said measurement of differential pressure Δpt and of said value of the operating power P, Pcor of said at least one engine, said first measuring component (7, 17, 27) and said second measuring component (8, 18, 28) being respectively connected to said at least one computer (9, 19, 29), characterised in that said evaluation system (12, 22) includes a third measuring component (11, 21) performing a speed measurement of said aircraft with respect to the surrounding air, said third measuring component (11, 21) being connected to said at least one computer (19, 29), said at least one computer (19, 29) being configured to determine a corrected differential pressure Δptcor of said differential pressure Δpt depending on said speed measurement of said aircraft with respect to the air, and in that said computer (9, 19, 29) is configured to generate said information by means of a clogging rate TCcor, said clogging rate TCcor being determined depending on said measurement of corrected differential pressure Δptcor, on a predetermined first limit Δpc and on a predetermined second limit Δpd at said operating power P, Pcor of said at least one engine, said first limit Δpc being a predetermined lower limit equal to a differential pressure value for a clean air filter at said operating power P, Pcor of said at least one engine, said second limit Δpd being a predetermined upper limit equal to a differential pressure value for a dirty air filter at said operating power P, Pcor of said at least one engine. • a first measuring component (7, 17, 27) performing a measurement of differential pressure Δpt between a reference pressure and a pressure measured upstream of said air filter in said air intake, • a second measuring component (8, 18, 28) enabling determination of a value of the operating power P, Pcor of said at least one engine, and • at least one computer (9, 19, 29) configured to generate said information under the dependence of said measurement of differential pressure Δpt and of said value of the operating power P, Pcor of said at least one engine, said first measuring component (7, 17, 27) and said second measuring component (8, 18, 28) being respectively connected to said at least one computer (9, 19, 29), characterised in that said evaluation system (12, 22) includes a third measuring component (11, 21) performing a speed measurement of said aircraft with respect to the surrounding air, said third measuring component (11, 21) being connected to said at least one computer (19, 29), said at least one computer (19, 29) being configured to determine a corrected differential pressure Δptcor of said differential pressure Δpt depending on said speed measurement of said aircraft with respect to the air, and in that said computer (9, 19, 29) is configured to generate said information by means of a clogging rate TCcor, said clogging rate TCcor being determined depending on said measurement of corrected differential pressure Δptcor, on a predetermined first limit Δpc and on a predetermined second limit Δpd at said operating power P, Pcor of said at least one engine, said first limit Δpc being a predetermined lower limit equal to a differential pressure value for a clean air filter at said operating power P, Pcor of said at least one engine, said second limit Δpd being a predetermined upper limit equal to a differential pressure value for a dirty air filter at said operating power P, Pcor of said at least one engine. characterised in that said evaluation system (12, 22) includes a third measuring component (11, 21) performing a speed measurement of said aircraft with respect to the surrounding air, said third measuring component (11, 21) being connected to said at least one computer (19, 29), said at least one computer (19, 29) being configured to determine a corrected differential pressure Δptcor of said differential pressure Δpt depending on said speed measurement of said aircraft with respect to the air, and in that said computer (9, 19, 29) is configured to generate said information by means of a clogging rate TCcor, said clogging rate TCcor being determined depending on said measurement of corrected differential pressure Δptcor, on a predetermined first limit Δpc and on a predetermined second limit Δpd at said operating power P, Pcor of said at least one engine, said first limit Δpc being a predetermined lower limit equal to a differential pressure value for a clean air filter at said operating power P, Pcor of said at least one engine, said second limit Δpd being a predetermined upper limit equal to a differential pressure value for a dirty air filter at said operating power P, Pcor of said at least one engine.