What specific action should a marshaller take if an aircraft continues taxiing beyond the designated stop point?

If an aircraft continues taxiing beyond the designated stop point, the marshaller must immediately execute a stop signal. This signal involves extending both arms above the head, crossing the wands or illuminated batons (if used) to form a distinct 'X' shape, and maintaining this position until the aircraft comes to a complete stop. Simultaneously, the marshaller must immediately establish radio communication with either the flight crew or ground control, reporting the overrun and the aircraft's new position. Clear and concise communication is crucial; the report should include the aircraft's call sign and its approximate distance beyond the intended stop line. After the aircraft has stopped, the marshaller, in coordination with ground control, should assess the situation to determine if the overrun has compromised safety or infringed upon any designated safety areas, such as taxiway or runway safety zones. If the overrun poses an immediate safety risk, the marshaller must continue communicating with ground control to initiate any necessary emergency procedures. The marshaller should not attempt to direct the aircraft backward without explicit authorization from both the flight crew and ground control. Doing so could create a hazardous situation, potentially leading to a collision with other ground vehicles or obstructions. Once clearance is obtained to move the aircraft, the marshaller must carefully guide the aircraft back to the designated stop point, ensuring constant vigilance and clear communication throughout the maneuver. A full incident report, detailing the circumstances of the overrun, must also be submitted to the appropriate airport authorities for further investigation and analysis to prevent future occurrences.