A convertiplane comprising: - a fuselage extending along a first axis; - a pair of cantilever wings (3, 3') projecting from respective sides of said fuselage; - a pair of nacelles housing respective engines and fixed with respect to said wings (3, 3'); and - a pair of rotors associated with said wings (3, 3'), rotatable about respective second axes and tiltable about a third axis transversal to said first axis and the respective second axis between: a first position, wherein said second axes are parallel to said first axis, reached when said convertiplane is in an aeroplane configuration; and a second position, wherein said second axes are orthogonal to said first axis and to said third axis, reached when said convertiplane is in a helicopter configuration; each said wing (3, 3') further comprising a wing box and a first movable appendage (22, 22') hinged to said wing box; each said first appendage (22, 22') being movable with respect to said wing box, when said convertiplane is in said aeroplane configuration, between: - a respective first neutral position with which a first lift value of the respective said wing (3, 3') is associated; - a respective second raised operating position with which a second lift value of the respective said wing (3, 3'), lower than said first lift value, is associated; and - a respective third lowered operating position, with which a third lift value of the respective said wing (3, 3'), higher than said first lift value, is associated; characterized in that each said wing (3, 3') further comprises a second appendage (21, 21') hinged to said wing box and selectively movable between: - a respective first neutral position, assumed when said convertiplane is in said aeroplane configuration and in which it defines an extension of said wing box; and - a respective second position, assumed when said convertiplane is in said helicopter configuration and in which it defines, with said wing box, an opening through which the downwash generated by the respective said rotor can pass. - a fuselage extending along a first axis; - a pair of cantilever wings (3, 3') projecting from respective sides of said fuselage; - a pair of nacelles housing respective engines and fixed with respect to said wings (3, 3'); and - a pair of rotors associated with said wings (3, 3'), rotatable about respective second axes and tiltable about a third axis transversal to said first axis and the respective second axis between: a first position, wherein said second axes are parallel to said first axis, reached when said convertiplane is in an aeroplane configuration; and a second position, wherein said second axes are orthogonal to said first axis and to said third axis, reached when said convertiplane is in a helicopter configuration; each said wing (3, 3') further comprising a wing box and a first movable appendage (22, 22') hinged to said wing box; each said first appendage (22, 22') being movable with respect to said wing box, when said convertiplane is in said aeroplane configuration, between: - a respective first neutral position with which a first lift value of the respective said wing (3, 3') is associated; - a respective second raised operating position with which a second lift value of the respective said wing (3, 3'), lower than said first lift value, is associated; and - a respective third lowered operating position, with which a third lift value of the respective said wing (3, 3'), higher than said first lift value, is associated; characterized in that each said wing (3, 3') further comprises a second appendage (21, 21') hinged to said wing box and selectively movable between: - a respective first neutral position, assumed when said convertiplane is in said aeroplane configuration and in which it defines an extension of said wing box; and - a respective second position, assumed when said convertiplane is in said helicopter configuration and in which it defines, with said wing box, an opening through which the downwash generated by the respective said rotor can pass. a first position, wherein said second axes are parallel to said first axis, reached when said convertiplane is in an aeroplane configuration; and a second position, wherein said second axes are orthogonal to said first axis and to said third axis, reached when said convertiplane is in a helicopter configuration; - a respective first neutral position with which a first lift value of the respective said wing (3, 3') is associated; - a respective second raised operating position with which a second lift value of the respective said wing (3, 3'), lower than said first lift value, is associated; and - a respective third lowered operating position, with which a third lift value of the respective said wing (3, 3'), higher than said first lift value, is associated; - a respective first neutral position, assumed when said convertiplane is in said aeroplane configuration and in which it defines an extension of said wing box; and - a respective second position, assumed when said convertiplane is in said helicopter configuration and in which it defines, with said wing box, an opening through which the downwash generated by the respective said rotor can pass.