A B737-200 CARGO DOOR OPENED IN FLT CAUSING RAPID DEPRESSURIZATION. AN EMER WAS DECLARED WITH A RETURN TO LAND.

Narrative

1) TKOF RWY BLEEDS OFF. 2) PASSING APPROX 2000 FT AGL WE BEGAN PRESSURIZING ACFT ON CLBOUT. 3) APPROX 7000 FT THE ACFT DEPRESSURIZED RAPIDLY AND A CARGO DOOR OPEN LIGHT ILLUMINATED. 4) ATTEMPTED TO CONTACT LCL ATC TO RETURN TO ARPT FOR LNDG. RADIO CALL WAS MISUNDERSTOOD AND FURTHER CLB CLRNC WAS ISSUED. 3 MORE XMISSIONS WERE SENT BEFORE WE WERE UNDERSTOOD. 5) WE RETURNED TO LAND WITHOUT FURTHER INCIDENT. WE ELECTED TO LAND IMMEDIATELY DUE TO THE CIRCUMSTANCES WHICH RESULTED IN AN OVERWT LNDG. EMER TRUCKS WERE STANDING BY. FACTORS: LANGUAGE BARRIER PLAYED A HUGE ROLE IN COMMUNICATING THE EXACT PROB AND OUR NEEDS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE REPORTER STATED THAT THE AFT DOOR DID ACTUALLY OPEN. BECAUSE THIS WAS A HIGH ALT BLEEDS OFF TKOF THE BLEEDS ARE OPENED AT SOME POINT DURING THE CLB AFTER TKOF. IN THIS CASE THE NON FLYING PILOT OPENED BOTH BLEEDS SIMULTANEOUSLY. THE REPORTER IS UNCERTAIN IF THE SUDDEN BLEED AIR SURGE IN THE PRESSURIZATION SYSTEM IS WHAT OPENED THE DOOR BUT THE TWO HAPPENED SIMULTANEOUSLY. THE EVEN BIGGER PROBLEM FOR THIS CREW WAS THE LANGUAGE BARRIER ATTEMPTING TO EXPLAIN TO ATC ABOUT THE NEED TO RETURN AND LAND.