RETURN LAND.

Narrative

OUR FLT PUSHED BACK FOR DEP. WE STARTED THE #2 ENG. OUR 'A' FLT ATTENDANT ENTERED THE COCKPIT AND INFORMED ME THERE WAS LIGHT SHOWING THROUGH THE FORWARD CABIN DOOR. HE ASKED IF HE SHOULD RECYCLE THE MAIN FORWARD CABIN DOOR. I CHKED THE DOOR ANNUNCIATOR WARNING LIGHTS. I PRESSED TO TEST THE ANNUNCIATOR LIGHTS. THE LIGHTS INDICATED THE DOOR WAS LOCKED. I ASSUMED THAT; WHEN THE ACFT WAS PRESSURIZED; THE DOOR SEAL WOULD GO FLUSH AGAINST THE FUSELAGE THUS CREATING A PRESSURIZED CABIN. THIS WAS NOT AN ABNORMAL EVENT IN THIS ACFT WHERE LIGHT WOULD SHOW THROUGH UNTIL PRESSURIZATION. WE TAXIED TO THE RWY. AFTER WE WERE AIRBORNE; THE ACFT WOULD NOT PRESSURIZE. THE FO WENT INTO THE CABIN TO DETERMINE OUR PROB AND DISCOVERED THE FORWARD MAIN ENTRY DOOR HAD NOT SEALED PROPERLY. WE WERE AT 7700 FT; TOLD ATC OF OUR PROB; AND LANDED WITHOUT FURTHER INCIDENT. THE DOOR WAS DIFFICULT TO OPEN. OUR FLT ATTENDANTS NOW INFORMED US THERE WAS A LARGE GAP WHEN THE DOOR WAS CLOSED AND THAT AT LEAST 1 PAX HAD NOTIFIED THEM OF THE LARGE GAP BTWN THE DOOR AND FUSELAGE. THIS UNFORTUNATELY WAS NOT INFO THEY HAD SUPPLIED EARLIER. IT WOULD PROBABLY HAVE INCLINED ME TO RETURN TO THE GATE INITIALLY. THIS INCIDENT POINTS OUT HOW NECESSARY AND CRITICAL INFO BTWN CABIN AND COCKPIT CREWS MUST BE CONTINUOUSLY EXCHANGED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES THE B-737 FOR A SECOND TIER ACR. THE FLT ATTENDANT THAT CAME TO THE COCKPIT WAS NOT VERY AGGRESSIVE IN HIS STATEMENT ABOUT THE DOOR PROB; SO THE FLC DECK CREW THOUGHT THAT THE PROB HAD SOLVED ITSELF WHEN THEY FOUND THAT THE DOOR ANNUNCIATOR LIGHTS CHKED 'OK.' THE FLT ATTENDANT DID NOT PASS ON THE PAX'S CONCERN ABOUT THE DOOR UNTIL AFTER RETURNING. THE FLT ATTENDANTS COULD NOT OPERATE THE DOOR ON THE GND; MAINT HAD TO COME ABOARD TO OPERATE THE DOOR. MAINT DID NOTHING TO CORRECT THE PROB -- JUST CYCLE THE DOOR. THE CAPT IS CONCERNED THAT THE GATE AGENT MADE NO MENTION OF THE DOOR. THE CAPT HAS HEARD NOTHING FROM EITHER THE FAA OR HIS CHIEF PLT ABOUT THIS.