Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Diverted; Flight Crew Returned To Departure Airport; General Maintenance Action
Human Factors; Procedure
1. On departure from ZZZZ; around 8;000' the cabin altitude indication turned amber. 2. Around 15;000' the cabin altitude turned red; and there was a Master Warning EICAS message ( [ ] CABIN ALTITUDE ) with the corresponding aural alerts 3. Crew performed the associated checklist for CABIN ALTITUDE 4. An emergency was declared and the crew descended 10;000' 5. IRO contacted dispatch on the SAT radio 6. Crew held; completed checklists; reviewed performance numbers; and set-up to return to ZZZZ 7. Crew received vectors for the ILS XXR into ZZZZ; and landed no further issues. 8. Maintenance met the airplane at parking spot X. 1.Prior to handing out paperwork; the Captain noticed a status message - 'Outflow Valve Aft' 2. Maintenance came on the airplane and worked the issue; and ended up writing one MEL (MEL 21.31.03.03.02) 3. We departed with a MEL on the AFT outflow valve; and ultimately ended up with the airplane not pressurizing correctly 4. After noticing the issue; followed by the Master Warning; the crew decided the best course of action was to return . Better communication between the maintenance team in ZZZ and the mechanics in ZZZZ. There seemed to have been a lapse in communication between the two groups. The ZZZZ mechanics looked to be rushed; and appeared to be struggling with accomplishing the MEL correctly.
Heavy Air Carrier First Officer reported communication failure between foreign maintenance and company maintenance team resulting in failure to repair aircraft.