AN A320 FORWARD CARGO DOOR BECAME UNLOCKED DURING DESCENT. AN EMERGENCY WAS DECLARED. AFTER LANDING THE DOOR LOCKING HANDLE WAS FOUND UNLATCHED; THE PRESSURE EQUALIZATION DOOR WAS OPEN; AND THE CARGO DOOR LOCK INDICATORS WERE RED.

Narrative

IN THE DSCNT TO ZZZ THE EICAS MESSAGE CAME ON INFORMING US THE FORWARD CARGO DOOR IS UNLOCKED. FO WAS FLYING; WE CONFIRMED THE EMER; AND COORDINATED OUR EFFORT; HE REMAINED THE PF AND SLOWED DOWN FROM 300 KIAS TO ABOUT 220 KTS AND EASED THE DSCNT. WE HAD BEEN INSTRUCTED TO CROSS ABC INTXN AT 12000 FT. I DECLARED AN EMER WITH CTR AND REQUESTED IMMEDIATE VECTORS TO ZZZ; THE CLOSEST; BIGGEST ARPT IN OUR MINDS. I STATED THE NATURE OF THE EMER AND THE NEED TO GET ON DECK QUICKLY. CTR SWITCHED US TO TWR AND THE TWR OFFERED US RWY 8L INSTEAD OF THE PLANNED OPERATING RWY OF 26R. I ACCEPTED; THE APCH LIGHTS WERE TURNED ON BRIGHT FOR RWY 8L. I CALLED THE FLT ATTENDANTS COLLECTIVELY AND TOLD THEM TO IMMEDIATELY BE SEATED AND DO A CABIN PREPARATION. GAVE THEM THE DETAILS OF WHAT WAS HAPPENING AND THE TIME REMAINING; LESS THAN 5 MINS. I SENT A QUICK ACARS MESSAGE TO DISPATCH AND THEN MADE A PA ANNOUNCEMENT TO THE PAX TELLING THEM WE HAD A CARGO DOOR COME UNLOCKED AND THE RAMIFICATIONS THAT POSED. I TOLD THEM TO GET IN THEIR SEATS; BUCKLE IN AND TO NOT GET UP UNTIL I RELEASED THE SEAT BELT LIGHT; ALSO PLEASE LISTEN AND PAY ATTN TO THE FLT ATTENDANTS. DURING MY ABSENCE TO THE RADIO; THE FO HAD THE COM. I CHKED BACK IN THE NET; WE WERE HIGH BUT OUR SINK RATE WAS SLOW AND OUR SPD WAS BACK; 210 KTS AND REDUCING. WE DISCUSSED THE POSSIBILITIES OF AN ENG FOD'ING AND FOR THE FO TO KEEP FLYING AND KEEP THE JET UNDER CTL. WE CONFIGURED FOR LNDG AND MADE A SMOOTH; UNEVENTFUL APCH AND LNDG TO RWY 8L. WE TAXIED TO THE GATE AND REQUESTED NOBODY OPEN THE CARGO DOOR UNTIL WE HAD A CHANCE TO LOOK AT IT. AFTER SHUTDOWN AND THE SECURING THE ACFT WE WENT OUTSIDE AND 2 CONTRACT MECHS WERE AT THE CARGO DOOR LOOKING AT IT. THE DOOR LOCKING HANDLE WAS STICKING OUT AT ABOUT A 30 DEG ANGLE FROM THE FUSELAGE; THE PRESSURE EQUALIZATION DOOR WAS FULL OPEN AND ALL THE CARGO LOCK INDICATORS BEHIND THE LITTLE ROUND GLASS VIEW SCREENS WERE RED. WE CHKED THE DOOR LOCKING MECHANISM AND FOUND THERE TO BE INTERFERENCE WITH THE SAFETY CATCH THAT SECURES THE MAIN LOCKING HANDLE. WITHOUT EXTRA ATTN TO LOCKING AND SEATING BOTH THE MAIN LOCKING HANDLE AND THE SAFETY CATCH; THE CATCH WOULD NOT SEAT AND ALLOW THE DOOR HANDLE TO OPEN IN THE WIND STREAM. THE FO AND I DEBRIEFED THE EVENT; I CALLED DISPATCH AND MAINT CTL TO ENSURE THE MAINT ITEM WAS FILLED OUT SO ACTION COULD BE TAKEN AND THEN WE WENT TO THE HOTEL.