A pantograph including: - a chassis to which a marking is attached, the marking including a longitudinal direction, a vertical direction, and a transverse direction, the longitudinal direction and the vertical direction together defining a vertical plane, - a bow intended to be in contact with a catenary to capture a power supply current flowing through the catenary, - an articulated arm linking the bow to the chassis is designed to vertically extend in order to move the bow in the vertical plane relative to the chassis, this articulated arm comprising at least one main rod and at least one auxiliary rod, each main rod and each auxiliary rod being substantially parallel and movable relative to each other, according to their common main axis, - an aileron assembly comprising at least one aileron movable relative to the articulated arm, - means for supporting the movable aileron, these support means being movably mounted on one amongst the main rod and the auxiliary rod, called support rod, - immobilisation means (4, 7), able to immobilise the support means with respect to the support rod, - orienting means, mounted on the other one amongst the main rod and the auxiliary rod, called orienting rod, these orienting means being able to move the support means relative to the support rod against the immobilisation means, these orienting means being adapted so that - over a first range of extension of the articulated arm in which the bow moves between a low position and an intermediate position, these orienting means do not act on the support means, so that a characteristic angle (α10) of the aileron, formed in the vertical plane by the movable aileron and the main axis of the support rod, is substantially constant; and - over a second range of extension of the articulated arm in which the bow moves between the intermediate position and a high position, these orienting means act on the support means, so that the characteristic angle of the aileron continuously varies. - a chassis to which a marking is attached, the marking including a longitudinal direction, a vertical direction, and a transverse direction, the longitudinal direction and the vertical direction together defining a vertical plane, - a bow intended to be in contact with a catenary to capture a power supply current flowing through the catenary, - an articulated arm linking the bow to the chassis is designed to vertically extend in order to move the bow in the vertical plane relative to the chassis, this articulated arm comprising at least one main rod and at least one auxiliary rod, each main rod and each auxiliary rod being substantially parallel and movable relative to each other, according to their common main axis, - an aileron assembly comprising at least one aileron movable relative to the articulated arm, - means for supporting the movable aileron, these support means being movably mounted on one amongst the main rod and the auxiliary rod, called support rod, - immobilisation means (4, 7), able to immobilise the support means with respect to the support rod, - orienting means, mounted on the other one amongst the main rod and the auxiliary rod, called orienting rod, these orienting means being able to move the support means relative to the support rod against the immobilisation means, - over a first range of extension of the articulated arm in which the bow moves between a low position and an intermediate position, these orienting means do not act on the support means, so that a characteristic angle (α10) of the aileron, formed in the vertical plane by the movable aileron and the main axis of the support rod, is substantially constant; and - over a second range of extension of the articulated arm in which the bow moves between the intermediate position and a high position, these orienting means act on the support means, so that the characteristic angle of the aileron continuously varies.