B777 flight crew reported malfunction of bleed air system which resulted in single pack operations during trans-oceanic flight. Flight crew returned to departure airport for precautionary landing.
Synopsis
B777 flight crew reported malfunction of bleed air system which resulted in single pack operations during trans-oceanic flight. Flight crew returned to departure airport for precautionary landing.
Narrative
After accomplishing Packs-Off takeoff from Runway XXL; the Pilot Monitoring (PM) completed the after-take off steps of the procedure by calling for the Pack switches to be turned back to on. Very soon after the Packs were turned back on (maybe 5-7 seconds); I noticed the 'Pack L + R' EICAS caution appear; then extinguish about 3-4 seconds later. About 10-15 seconds later; there then seemed to be a simultaneous illumination of the 'BLEED LOSS WING R'; the 'BLEED OFF ENG R'; and the 'PACK R' EICAS caution messages. The Pilot Flying (PF) engaged the autopilot and assumed radio communication duties. The PM (Captain) then started to run the activated EICAS Non-normal checklists; with help from the 2 Relief Pilots. We continued to climb as the checklists were completed. The Left pack; powered by the Left engine bleed; air seemed to keep the aircraft pressurized normally. The Captain initiated a SATCOM call with Dispatch; who quickly brought Maintenance Control in on a conference call with the Captain; with both Relief Pilot's listening in. I don't recall the specifics of the conversation; I just remember that Dispatch did not find anything in any written guidance or policy that would forbid a continued flight into ORCA (Oceanic Route Clearance Authorization) and ETOPS airspace with this specific problem (that is; only one Pack available). The flight crew's interpretation of the Non-normal checklist verbiage was that the Right isolation valve (now apparently closed by system logic) was never going to let either of the remaining bleed sources power the right pack in the event of left pack failure. Maintenance Control couldn't seem to provide any further guidance to our situation. At one point the Maintenance Control representative asked if there wasn't a procedure to try to reset the inoperable valve. We reminded him that there was--but only if this non-normal procedure (BLEED OFF ENG R) was being run while the aircraft was still on the ground.After a quick discussion amongst all four pilots; it was clear that none of us were comfortable continuing on a 12 hour flight with this malfunction. The Captain informed Dispatch of our intent to return and asked if the company wanted us to land at ZZZZ or ZZZZ1. Dispatch asked us to take the aircraft back to ZZZZ. We explained our situation to ZZZZ Control and received immediate clearance back towards the airfield. We initiated the procedure to get our landing weight back below max landing weight. This was done over the ocean east of Country X between the altitudes of 29;000 and 16;000 feet (approximately). We did not feel a need to [request priority handling] from ATC; and were actually given about 3 or 4 turns in holding to ensure we were done dumping fuel while still over water. ATC gave us vectors for an approach to Runway XXR. The approach; landing; and taxi to park proceeded without further incident.
Second reporter narrative
We departed XXX with packs off by referencing the supplementary procedure and turned the packs off at least 30 seconds prior to adding takeoff thrust. After the first thrust reduction; 1;500 ft.; we turned the packs back on roughly climbing thru 2;000 ft. Shortly thereafter we received two EICAS messages; BLEED OFF ENG R and BLEED LOSS WING R; and a STATUS message BLEED FAMV R. After noting these I turned the autopilot on to help with workload management. The captain/PM ran the corresponding checklist which configured the aircraft with the right bleed valve switch in the off position; the right isolation valve closed but the switch still in the auto position; and the right pack off. After we cleared the terminal area I took over the radios and the PF roles while the captain and relief officers called Maintenance Control and Dispatch. It was decided and agreed by all that the best course would be to return to XXX. While still at F290 near ZZZZZ we coordinated with ZZZZ Approach the dumping of 154;100 lbs of fuel; which ended at F160 while holding at MILIT. We didn't [request priority handling] and didn't have any equipment standing by in XXX. We were cleared on the ZZZZZ STAR and RNP Rwy XXR approach. A normal flaps 30/auto brakes 4 approach was selected and executed.
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.