DC-10 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem
Aircraft; Procedure
Received a cabin altitude warning at cruise approximately 1 hour 20 minutes into flight. [Immediate action steps] were completed and complied with QRH procedures regaining control of the cabin using manual control. Jumpseater was a qualified crewmember and properly donned his mask and responded to cockpit request for communication check.  The First Officer did an excellent job running the checklist and manually controlling the cabin altitude. The rest of the flight was uneventful.I will say that a change in that checklist is in order. After the [immediate action steps] were complete; the crew should have been able to cycle through manual; back to automatic to attempt to change to a functional controller. By adding this to the checklist; a crew would not be forced to run the system in manual for the remainder of the flight per the QRH.
A DC-10 Captain reported losing automatic cabin pressurization control. After running the procedure the flight continued in manual pressurization mode.