What was found
AC DID NOT PRESSURIZE, GOT ALTITUDE WARNING AT 10,000. MAIN CARGO DOOR INDICATED NOT CLOSED PROPERLY. DUMPED FUEL & RETURNED TO CDG. LANDED AT 568,000# AT ARRIVAL FOUND VENT MAIN CARGO DOOR PARTIALLY CLOSED AND LATCH LIGHT NOT ILLUMINATED . MAIN CARGO TEST AND OPARATE MULTIPLE TIMES IAW AMM 52-32-00-5. ALL TEST PASSED.