Date: 201203
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Pneumatic Valve/Bleed Valve
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Human factors: Communication Breakdown; Human-Machine Interface
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Human Factors

Narrative: The Engine Bleed switches were in the off position for takeoff. Somehow we missed it on the Before Takeoff Checklist. While running the Climb Checklist at 10;000 MSL; we noticed the plane was not pressurizing; and started a level-off. At approximately 11;000 MSL; we got the Cabin Altitude Warning Horn. We leveled off; put on oxygen masks; and informed ATC we needed to descend to 10;000 MSL and they approved. We leveled at 10;000 MSL and the horn stopped. We then ran the Abnormal Pressurization; Cabin Altitude Warning Horn Checklist; and realized both Engine Bleed switches were off. One at a time; per the checklist; we turned the Engine Bleed switches on and the plane pressurized. We checked with the flight attendants to make sure the oxygen masks in the back did not drop; and that no one in the back was having any issues. They informed us that everybody and everything in the back was fine. We coordinated with ATC and continued. We sent a message to Dispatch with a brief description and our intentions to continue. The rest of the flight was uneventful. We did run all the normal checklists but did not properly crosscheck with our responses. It was not a planned bleeds off takeoff. I don't know for sure when the engine bleeds were placed in the off position. Proper preflight and better attention to the crosscheck during checklist challenge and response would have prevented this from happening.


Second narrative: We determined that the Engine Bleed switches were in the off position when we took over the aircraft at the gate. This is not an abnormal situation; however; it is not typical. Our expectations then led us to not carefully and thoroughly verify [and set] the [correct] setting. We had several chances through flows and checklists to remedy the situation before we arrived at the runway. We didn't and our last chance was hurried by an immediate takeoff clearance...in the future I plan to adopt a touch (or at least point) technique when accomplishing checklist items to focus my attention on the actual setting and not just the verbal responses. I further plan to reevaluate my pacing to ensure my aircraft operation is not compromised by a false sense of a need to rush.']


Synopsis: A B737-700 flight crew failed to note both Engine Bleed switches were off despite running predeparture checklists which required them to be in the on position. The error was discovered and corrected when the cabin altitude warning horn sounded.