Date: 201210
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Dawn
Aircraft: Q400
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Pressurization Control System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Commercial
Human factors: Situational Awareness; Training / Qualification; Workload
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew; Person Maintenance
When detected: Aircraft In Service At Gate; In-flight
Result: Flight Crew FLC complied w / Automation / Advisory; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: First flight of the day for us; early morning departure; [we] got to the airplane; preflight; taxi; takeoff; everything as normal. During the climb out; passing through 12;000 FT; we got a CABIN PRESSURE warning light. Immediately went to the appropriate emergency checklist. Also; simultaneously coordinated with ATC to maintain 12;000 FT and then very soon after a decent to 10;000 FT. As we were going through the emergency checklist we were also getting closer to an en route maintenance station and got a decent to 8;000 FT. Our flight was scheduled to go to a more distant airport; but due to this pressurization issue; we knew we would have to make our way to our filed destination at 8;000 instead of the planned altitude. We talked to Dispatch to help verify that we would have enough fuel for an 8;000 FT flight to our filed destination. We had also considered landing at the nearby airport; however; we had plenty of fuel to continue the flight to our filed destination. We continued to our filed destination and made a normal landing.After ending the flight I left the airplane to go to preflight another airplane for our next flight. My Captain stayed at the airplane to make a maintenance entry and talk to Maintenance people. When he met up with me again; he did mention that there was a circuit breaker or breakers that were popped. I had not seen it for myself; but thought that was plausible since we did have an anomaly. After; I did not think about this event again. The next day; I was notified by company that there could have been popped circuit breakers prior to the flight. During my preflight I did not notice any popped circuit breakers. In fact; during the flight while dealing with the issue; the Captain and I both checked our respective circuit breaker panels and did not notice anything out of order; although it is possible that we could have missed seeing a popped circuit breaker. I do not know if there was a popped breaker or if a breaker had popped in flight. In fact; I never saw a popped circuit breaker for myself. I knew about it from the mention of it from my Captain after the fact and then in the notification from company. The aircraft had a pressurization malfunction. After the fact; I was notified that it could have been the circumstance that it could have been a popped breaker or breakers prior to our flight departing. If that was the case; then it would be human error with complacency since I had not noticed any popped circuit breakers prior to the flight. I do not know if any breakers were popped prior to the flight or if they had popped during the flight.




Synopsis: A Q400 crew was notified their flight's pressurization malfunction and CABIN PRESSURE Warning may have resulted because circuit breakers were popped prior to or during preflight and went undetected.