What was found
(CAN) AS COLLECTIVE WAS LOWERED FLIGHT CREW HEARD A (WHOOSH) SOUND FOLLOWED BY AN ENG N1 UNDER-SPEED WARNING AUDIO. FLIGHT CREW VERIFIED ENG, IMMEDIATELY EXECUTED AN IN-FLIGHT SHUTDOWN OF NR 1 ENG TO PREVENT OVER-TEMP CONDITION. WITH NR 1 ENG SHUTDOWN, AC RETURNED TO ITS SERVICE AREA WITHOUT FURTHER INCIDENT. INSP OF ENG, ITS RELATED CONTROL LINKAGES REVEALED NOTHING ABNORMAL. ENG FUEL PRESSURIZING, DUMP VALVE (P&D VALVE) WAS CHANGED AS A STANDARD PROCEDURE IN A SOFT STALL OCCURRENCE. ADDITIONALLY, FCU WAS ALSO CHANGED AS PRECAUTIONARY MEASURE. ENG WAS RESTARTED, GROUND-RUN, FOUND TO BE ACCEPTABLE AC WAS RELEASED FOR FLIGHT. THE SUSPECT COMPONENTS WERE RETURNED TO MFG FOR INTERNAL INSPECTION, EVALUATION.