Date: 201203
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Aircraft component: Exterior Pax/Crew Door
Component problem: Malfunctioning; Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Workload; Confusion; Time Pressure; Communication Breakdown
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight; Aircraft In Service At Gate
Result: Flight Crew Diverted; General Maintenance Action; General Declared Emergency
Contributing factors: Aircraft; Procedure
Primary problem: Procedure

Narrative: This aircraft had MEL 52-70-0101 regarding the passenger door proximity system. I reviewed the MEL; and briefed the crew on what was to be expected including the Flight Attendant on checking the alignment markings and the lock position on the passenger door and un-stowing and re-stowing the outer handle push/actuator on the door lever; all required actions for the MEL. I briefed the ramp personnel to confirm that the outer handle was stowed after the passenger door was closed; and they complied by confirming so. At the gate; I had noticed that there was a PAX DR OUT HNDL caution message and recalled that the MEL had briefly mentioned the outer handle in the notes section. When the Flight Attendant initially performed the action with the pulling and re-stowing of the outer handle the message did not clear. I asked her to perform this action again just to make sure; and the message cleared. During pushback; the message reappeared. I called Dispatch and explained the situation. I also informed Dispatch that I didn't believe that this message was allowed per this MEL. We set up a three way conference call that included the Dispatcher; Maintenance Control; and me. Maintenance Control reviewed the MEL; and told me that the brief mentioning of the outer handle in the notes implied that this message; along with the OVB COOL FAIL message would disappear 15 seconds after take-off. I said that I felt like it was only referring to the OVB COOL FAIL message; and he said this one should clear as well. He continued to tell me that if it didn't clear to contact him in flight. I was a bit reluctant to continue the flight since the wording in the MEL was unclear to me; and the information from Maintenance Control didn't seem to match up with the MEL. I couldn't find anywhere in the MEL that specifically allowed for the PAX DR OUT HNDL message to be present. I considered that I knew that the passenger door was safely secure regardless; and went with what Maintenance was telling me. Shortly into the flight; I watched as the OVB COOL FAIL message disappeared as predicted in the MEL while the PAX DR OUT HNDL caution message remained. We ran the QRH; and I called the Flight Attendant and walked her through the part concerning the outer handle stowing mechanism. This did not clear the message; and furthermore; briefly produced a Passenger Door Warning message in the process. The next step in the QRH was 'land at nearest suitable airport.' I made several attempts to relay the situation to headquarters via ACARS. I decided that I should divert to the nearest suitable airport which in my opinion was a nearby en route airport. Eventually; Dispatch contacted me; and we agreed to divert to the en route airport. In the process; I decided to use my emergency authority; especially since we had no alternate and now a new destination that was not on the release. I also considered that there may have actually been a separate and serious problem with passenger door which was the ultimate and final factor in my declaring an emergency. We continued the flight to divert airport with no further disruption. I should have considered that the original write-up in the logbook was due to a crew receiving a PAX DOOR STOW caution message in flight and that the PAX DR OUT HNDL caution is a different message most likely dealing with another proximity sensor. Furthermore; I should have stuck to my opinion that this was a separate problem and not part of the MEL. In the future; I should further question Maintenance Control for their reasoning and not continue a flight that I feel could have a problem that is not already addressed by an MEL or maintenance action.


Second narrative: [Narrative 2 contained no additional information]


Synopsis: A CRJ200 alerted a caution message PAX DR OUT HNDL so the system was MEL'ed but after takeoff the alert did not cease as predicted so the flight diverted to an enroute airport for maintenance.