Narrative:

On departure climb out; we received a call from our a flight attendant. She indicated that she was hearing a loud hiss from the forward entrance door after the ten thousand foot ding. We elected to continue our climb as the pressurization seemed relatively normal at this point; and we hoped the door seal would seal itself as the cabin psi increased. I asked the a to call us back if the hiss continued. ATC continued our climb clearances to our cruise altitude. Our a called back and said the loud hiss continued. We leveled off at FL290 to check cabin rate. The cabin was climbing at 900 to 1000 ft per min. We notified ATC that we had a pressurization problem and need lower quickly and we planned to return. We received initial clearance to 17;000' and then later to 13;000'. We descended at max rate. Our cabin altitude warning went off; we did our memory items; donned our O2 masks and turned back toward ZZZ airport. We declined to declare an emergency as our descent clearance came quickly and our cabin altitude never climbed above 11;000 ft; with 6 psi of pressure. At this point we went direct to the field and were given further step down altitudes as terrain allowed. We landed without further incident.

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Original NASA ASRS Text

Title: B737 flight crew is advised during climb by the A Flight Attendant that the forward cabin door has a loud hiss. Approaching FL290 the crew requests a level off then a descent when the cabin continues to climb. The cabin altitude warning horn sounds as descent is commenced and the flight returns to departure airport.

Narrative: On departure climb out; we received a call from our A Flight Attendant. She indicated that she was hearing a loud hiss from the forward entrance door after the ten thousand foot ding. We elected to continue our climb as the pressurization seemed relatively normal at this point; and we hoped the door seal would seal itself as the cabin PSI increased. I asked the A to call us back if the hiss continued. ATC continued our climb clearances to our cruise altitude. Our A called back and said the loud hiss continued. We leveled off at FL290 to check cabin rate. The cabin was climbing at 900 to 1000 ft per min. We notified ATC that we had a pressurization problem and need lower quickly and we planned to return. We received initial clearance to 17;000' and then later to 13;000'. We descended at max rate. Our cabin altitude warning went off; we did our memory items; donned our O2 masks and turned back toward ZZZ airport. We declined to declare an emergency as our descent clearance came quickly and our cabin altitude never climbed above 11;000 ft; with 6 psi of pressure. At this point we went direct to the field and were given further step down altitudes as terrain allowed. We landed without further incident.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.