B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 241
Distraction; Situational Awareness; Time Pressure
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Company Policy; Procedure; Human Factors
Ground Operations had run the APU all night for heat and had turned off the Engine Bleed switches. Only the APU Bleed switch was on. We missed catching it during our flows. Upon reaching the runway; we were expecting to wait for the traffic we saw on final; but Tower cleared us for takeoff. The Takeoff Checklist was hurried and with expectation bias we again missed that the engine bleeds were off. Taking ATC calls and talking about the aircraft on final kept us from recognizing that things weren't right; ears popping; etc. Center cleared us to climb to FL230. Climbing through 10;000 ft we ran the climb check. Once again expectation bias let me see the cabin climbing normally. I don't recall checking the cabin altitude. Climbing through 14;000 ft the Cabin ALT horn/light went off. I immediately saw the problem and turned the Engine Bleed switches on; called Center for a level off and descent to 10;000 ft. The cabin pressure returned to normal and after we felt all was stable we resumed our climb and continued the flight. I called the FAs (Flight Attendants) to check if the masks had fallen and to check if anything seemed abnormal to them. They said that they felt the pressure bump; but everything was ok other than more than normal noise around the door. The rest of the flight was non-eventful.
B737 Captain reported a Cabin Alt warning after taking off with the packs selected off.