Drilling system and method

A drilling method carried out using the drilling system comprising a support structure to be mounted on a surface to be drilled, a beam supported by the support structure, a tool holder supported by said beam, said tool holder having a locking orifice, and a drilling tool mounted on said tool holder for drilling in the direction of a drilling axis, wherein a mounting of the tool holder on the beam and a mounting of the drilling tool on the tool holder each comprise a sliding connection which permits sliding in a direction parallel to the drilling axis defined by said tool, wherein said drilling tool comprises a bearing mandrel intended to come into contact against the surface to be drilled, and an expandable ring closely fitting the bearing mandrel along a tapered contact surface and adapted so that a relative movement along a tapered contact surface central axis between the bearing mandrel and the ring procures an expansion of said ring capable of ensuring its locking in the locking orifice,

• the method comprising at least one step of drilling a hole, wherein, for each step of drilling a hole, a relative movement is applied between the expandable ring and the bearing mandrel,
• wherein the application of said relative movement between said expandable ring and said bearing mandrel is done so as to create a movement of the bearing mandrel against said surface to be drilled and through said locking orifice, over a distance x2 respecting the condition x2>0.90·x, where x corresponds to a total distance of the relative movement applied between the ring and the mandrel, and
• wherein the relative movement between the ring locked in the locking orifice and the bearing mandrel procures, by movement of the drilling tool relative to the tool holder via the slide connection, a movement of the bearing mandrel towards the surface to be drilled, through the locking orifice.