What was found
3930 DURING CLIMBOUT AROUND 13K FEET HEARD LOUD HISSING SOUND COMING FROM BEHIND THE FLIGHT DECK. FA CALLED AND SAID IT WAS FROM THE MAIN CABIN DOOR. AROUND 19K FEET HISSING GOT LOUDER AND CABIN RATE RAPIDLY INCREASED. CABIN ALTITUDE NEVER EXCEEDED 6K FEET. NO MESSAGES REGARDING MAIN CABIN DOOR. DURING DESCENT PRESSURIZATION NORMAL. ***AIRCRAFT REMOVED FROM SERVICE*** FOUND A TEAR IN PAX DOOR SEAL. R&R PAX DOOR SEAL IAW AMM 52-11-10. REF . 342366/3 FOR OPS CHECK