Narrative:

On climbout through 17;000 ft; the fuselage doors warning illuminated. Aft passenger door annunciated not secure. By direction of checklist; contacted flight attendants and they reported handle was not secure. We requested; received and complied with revised clearance to return to departure field. Complied with rest of east&a for fuselage doors and unpressurized flight. Contacted dispatch to revise destination. After landing; instructed flight attendants and station to not touch aft cabin door. Maintenance came on board and found the handle to not be secure. Maintenance tested and verified proper door operation and signed off aircraft for continued flight. I sat in the maintenance room while mechanics were talking to maintenance control. Apparently this is the 4th time in 2 months that this has happened on this tail number. Maintenance seems to believe that the flight attendants are not closing the door properly because it is a new tail number and the door is 'tight.' if this is the case; revised guidance must be issued to flight attendants. I am not sure that a door should annunciate secure if it is not; in fact; secure for flight. I discussed this with maintenance and they measured the tolerances on the annunciator micro switches and found them to be within limits. Tolerances or not; since this seems to be isolated to this tail number; I'd suggest that this particular door be looked at more closely. After the high-stress of a flight that involved depressurizing; etc.; it is very upsetting to know that this has happened before on this particular tail number and the problem hasn't yet been rectified. I only felt comfortable taking the aircraft again because the mechanic trained the flight attendant how to close the door 'properly;' although I do not believe she was closing it 'improperly' according to her training.

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Original NASA ASRS Text

Title: A DHC8-400 (Q-400) aft cabin door did not completely close before takeoff causing a FUSELAGE DOORS warning in flight. After a return to land the crew was told this was the fourth aft cabin door event for this same aircraft.

Narrative: On climbout through 17;000 FT; the FUSELAGE DOORS warning illuminated. Aft Passenger Door annunciated not secure. By direction of checklist; contacted Flight Attendants and they reported handle was not secure. We requested; received and complied with revised clearance to return to departure field. Complied with rest of E&A for Fuselage Doors and Unpressurized Flight. Contacted dispatch to revise destination. After landing; instructed Flight Attendants and station to not touch aft cabin door. Maintenance came on board and found the handle to not be secure. Maintenance tested and verified proper door operation and signed off aircraft for continued flight. I sat in the maintenance room while mechanics were talking to Maintenance Control. Apparently this is the 4th time in 2 months that this has happened on this tail number. Maintenance seems to believe that the Flight Attendants are not closing the door properly because it is a new tail number and the door is 'tight.' If this is the case; revised guidance must be issued to Flight Attendants. I am not sure that a door should annunciate secure if it is not; in fact; secure for flight. I discussed this with maintenance and they measured the tolerances on the annunciator micro switches and found them to be within limits. Tolerances or not; since this seems to be isolated to this tail number; I'd suggest that this particular door be looked at more closely. After the high-stress of a flight that involved depressurizing; etc.; it is very upsetting to know that this has happened before on this particular tail number and the problem hasn't yet been rectified. I only felt comfortable taking the aircraft again because the Mechanic trained the Flight Attendant how to close the door 'properly;' although I do not believe she was closing it 'improperly' according to her training.

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.