A method of actuating undercarriage latching boxes and associated hatch latching boxes of an aircraft in an emergency mode, the latching boxes having at least one feed port and at least one unlatching member that is operable when the port is fed with fluid under pressure, the aircraft also being provided with a hydraulic braking circuit. The method includes connecting at least one tapping circuit to the braking circuit of the aircraft in association with an isolation valve that is kept, in a normal mode, in an isolation state and that can be controlled to be placed in an open state in which at least some of the feed ports of the latching boxes are fed by the tapping circuit connected to the braking circuit.