B737-700
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 309; Flight Crew Type 13000
Aircraft Equipment Problem Critical; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Flight Crew Diverted; Flight Crew Landed As Precaution
Aircraft
While at FL410 we experienced a Cabin Altitude Warning horn and light. We donned O2 mask and established communication. We followed the QRC checklist and were able to get the cabin to stabilize at approximately 10;200 feet. We had no green ALT light on the pressurization control panel leading us to believe we had a dual controller failure. We followed the Emergency Descent QRH and advised ATC and Dispatch of our intentions. We chose [a nearby alternate] as a diversion point. The cabin began to be in the normal range as we went through about 15;000 feet. We landed without incident.
I think the Captain and I handled the situation in a cool and collected manner. After finishing the checklists; I mentioned that I should have waited for the Captain to respond with the appropriate calls per the checklist in use. I would read the item and response with the appropriate call. He agreed but said that given the nature of what was going on with us in a rapid descent; he felt it went well; and that the checklists were accomplished correctly and in the proper order. I would like to note also that once you are lead to an emergency descent; it never takes you back to the other checklist; the Cabin Altitude Warning; which has an important step of modulating the outflow valve to open by pattern altitude. The Captain mentioned that and we did modulate it on our own to full open by pattern altitude.
B737-700 flight crew reported diverting to an alternate airport after experiencing loss of cabin pressure at FL410.