Date: 201201
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Icing; Snow; 1
Light: Daylight
Aircraft: Dash 8 Series Undifferentiated or Other Model
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: Pneumatic Valve/Bleed Valve
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Distraction; Training / Qualification; Situational Awareness
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Attendant
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented; General Maintenance Action
Contributing factors: Human Factors; Environment - Non Weather Related; Weather
Primary problem: Human Factors

Narrative: While departing on climb out we missed turning on the bleed air system. The weather was low overcast and the visibility was 1 mile. Our initial indication was a call from the Flight Attendant letting us know that the oxygen masks had deployed. This occurred climbing through 12;500 FT. Upon receiving this information we immediately turned on the bleed air system and checked that the aircraft was pressurizing properly. Our final cruise altitude was 13;000 FT. We continued the flight to our filed destination normally. Contributing factors that lead to our missing the bleed air system were: task saturation due to high elevation airport; weather; and Air Traffic Control frequency changes while on the IFR departure procedure; and the Master Warning Flasher to indicate a pressurization problem climbing through 10;000 FT not working properly. My Captain normally reaches to turn on the bleed air on his after takeoff flow. However; he needed to make sure that the de ice boots were on as we were climbing into icing conditions on this particular flight; thus interrupting his flow. At acceleration altitude we also changed from Tower to Center. I was flying the IFR departure procedure and my Captain was backing me up; as he should. Only having 3;000 FT to climb; he had not gotten to the climb check reaching 10;000 FT; which would have been another way to have caught that the cabin was not pressurizing before the oxygen masks dropped. We did not get a Master Warning Flasher indicating a pressurization issue. After the masks dropped; we discovered that some of the masks did not drop properly. Upon termination of the flight; the Oxygen masks; the oxygen masks that did not work properly; and the Master Warning Flasher were properly written up. A future event might be prevented if the after takeoff checklist were said out loud as the climb check is or If we could take off with the bleeds on with low ceilings at a high elevation airport.




Synopsis: A DHC8's oxygen masks dropped at 12;500 FT after the bleeds were not OPEN because the Captain was distracted managing the wing deice boots and the cabin pressurization warning system failed.