B777 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
Air Traffic Control Provided Assistance; Flight Crew Took Evasive Action; Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Company Policy; MEL; Manuals; Procedure
Status MSG outflow valve aft found on preflight. Put in logbook and item was deferred. Took off and passing 8;000 feet got cabin altitude caution message followed by cabin altitude warning at 14;000 feet on Eicas. We donned the oxygen mask ran the associated checklist. We would need to descend to 10;000 feet and hold [and advised ATC]. Entered holding; configured airplane for approach and made an uneventful landing.
B777 Captain reported loss of cabin pressure on climb out caused an expedited descent and an air turnback to a precautionary landing.