Abstract: An aircraft undercarriage comprising: a leg connected to an aircraft structure to be movable between a deployed position and a retracted position; a brace member for holding the leg in its deployed position and comprising a first rod hinged to the aircraft structure and a second rod hinged to the first link and to the leg; a stabilizer member for holding the first and second rods in an aligned position and comprising a first link and a second link that are hinged to each other, with at least one of them being hinged to the brace member; and a spring for elastically urging the hinges of the first and second links into a generally aligned position. The spring comprises at least one spring blade arranged to be subjected to an axial compression force when the first and second links leave the generally aligned position.