B737-700
Flight Crew Last 90 Days 164
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport
Human Factors
Climbing thru approximately 12;000 feet; the Cabin Altitude Warning light illuminated along with the Cabin Altitude Warning horn sounding. The First Officer (FO) was flying and I directed him to immediately descend. I notified ATC of the situation and was cleared to 9;000 feet. While descending I ran the QRC and at 9;000 feet the QRH and briefed the Flight Attendants. I determined that the pressurization could not be controlled. I made a brief PA to the Passengers that we had a pressurization issue and were returning to [departure airport]. I called Operations on Company radio to apprise them and that I was returning to land. Dispatch was notified via ACARS of my intentions to land. The aircraft landed uneventfully and was met by a Customer Service Agent to assist the passengers. I have been told by my Chief Pilot that the bleeds were left off. Make sure ALL checklist items are CHECKED. Apparently the engine bleed switches were missed by both pilots; 'what you want to see is NOT necessarily what you see!'
[Report narrative contained no additional information.]
B737-700 flight crew reported returning to departure airport after the aircraft failed to pressurize. Later; engine bleed switches were found to be in the off position.