What was found
AIR TURN BACK, ON CLIMB OUT, EN ROUTE, RECEIVED ECAM WARNING FOR FORWARD CARGO DOOR WARNING INDICATION, TURNED BACK AND LANDED WITHOUT FURTHER EVENT. MAINTENANCE INSPECTED FORWARD CARGO DOOR AND FOUND IT SECURE, ISSUED MEL 52-70-01, COND. 1 (FWD CARGO DOOR INDICATION INOP), ORDERED PROXIMITY SENSOR. MAINTENANCE FOUND FORWARD CARGO DOOR PROXIMITY SENSOR POSITION TARGET OUT OF ADJUSTMENT; ADJUSTED TARGET IAW AMM 52-71-00-05, OPERATIONAL CHECK WAS GOOD.