Narrative:

On dec/xa/00 flight cvg-abe, a passenger door master warning occurred at approximately 2500 ft. We leveled at 3000 ft and returned for landing while running the QRH emergency procedure. The procedure called for selection of the manual mode and a full rate increase of the cabin altitude. After selecting the increase position there was still a slight positive pressure indication of approximately -.2 delta P. This was of concern to us and I elected for a delay vector to call maintenance and clarify if this indication would cause any problems upon landing. I was under the impression that upon weight on wheels, the aircraft would unpressurize as it does normally in automatic mode. This is not the case it turns out. Maintenance indicated they didn't see any problem. After taxiing the aircraft to the gate and completing the parking checklist, the flight attendant said she was having difficulty opening the main cabin door. It did nt occur to me that this may have been pressure related. I was in the process of getting up to help when the door basically flew open. She was holding onto the step/handle and fell forward with the door. She suffered only minor scrapes on her legs and requested no first aid. I believe that I followed the QRH procedure correctly. In any case, if the pressure remained on the aircraft due to a faulty pressure system or an incorrectly run procedure, an emergency depressurization after landing would ensure that no residual pressure could remain unless there happened to be a major malfunction of the outflow valves. Selection of the emergency depressurization button was previously included in the QRH procedure, but was removed for other reasons. It was at the start of the checklist for high altitude sits. If it were reinserted at the end after landing, this would alleviate the problem I indicated.

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Original NASA ASRS Text

Title: FLC OF A CANADAIR CL65 RETURNED TO LAND AFTER THE DOOR MASTER WARNING LIGHT ILLUMINATED.

Narrative: ON DEC/XA/00 FLT CVG-ABE, A PAX DOOR MASTER WARNING OCCURRED AT APPROX 2500 FT. WE LEVELED AT 3000 FT AND RETURNED FOR LNDG WHILE RUNNING THE QRH EMER PROC. THE PROC CALLED FOR SELECTION OF THE MANUAL MODE AND A FULL RATE INCREASE OF THE CABIN ALT. AFTER SELECTING THE INCREASE POS THERE WAS STILL A SLIGHT POSITIVE PRESSURE INDICATION OF APPROX -.2 DELTA P. THIS WAS OF CONCERN TO US AND I ELECTED FOR A DELAY VECTOR TO CALL MAINT AND CLARIFY IF THIS INDICATION WOULD CAUSE ANY PROBS UPON LNDG. I WAS UNDER THE IMPRESSION THAT UPON WT ON WHEELS, THE ACFT WOULD UNPRESSURIZE AS IT DOES NORMALLY IN AUTO MODE. THIS IS NOT THE CASE IT TURNS OUT. MAINT INDICATED THEY DIDN'T SEE ANY PROB. AFTER TAXIING THE ACFT TO THE GATE AND COMPLETING THE PARKING CHKLIST, THE FLT ATTENDANT SAID SHE WAS HAVING DIFFICULTY OPENING THE MAIN CABIN DOOR. IT DID NT OCCUR TO ME THAT THIS MAY HAVE BEEN PRESSURE RELATED. I WAS IN THE PROCESS OF GETTING UP TO HELP WHEN THE DOOR BASICALLY FLEW OPEN. SHE WAS HOLDING ONTO THE STEP/HANDLE AND FELL FORWARD WITH THE DOOR. SHE SUFFERED ONLY MINOR SCRAPES ON HER LEGS AND REQUESTED NO FIRST AID. I BELIEVE THAT I FOLLOWED THE QRH PROC CORRECTLY. IN ANY CASE, IF THE PRESSURE REMAINED ON THE ACFT DUE TO A FAULTY PRESSURE SYS OR AN INCORRECTLY RUN PROC, AN EMER DEPRESSURIZATION AFTER LNDG WOULD ENSURE THAT NO RESIDUAL PRESSURE COULD REMAIN UNLESS THERE HAPPENED TO BE A MAJOR MALFUNCTION OF THE OUTFLOW VALVES. SELECTION OF THE EMER DEPRESSURIZATION BUTTON WAS PREVIOUSLY INCLUDED IN THE QRH PROC, BUT WAS REMOVED FOR OTHER REASONS. IT WAS AT THE START OF THE CHKLIST FOR HIGH ALT SITS. IF IT WERE REINSERTED AT THE END AFTER LNDG, THIS WOULD ALLEVIATE THE PROB I INDICATED.

Data retrieved from NASA's ASRS site as of July 2007 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.