Date: 201503
Location: UHMM.ARTCC, FO
Flight conditions: VMC
Weather elements / visibility: Volcanic ash
Light: Dusk
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center UHMM
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Captain
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Contributing factors: Environment - Non Weather Related
Primary problem: Environment - Non Weather Related

Narrative: Shortly after passing BUMAT at FL350 on B337; Magadan ATC gave us a PIREP of Volcanic Ash ahead near our intended course. Volcanic ash (VA) was reported at GORAS FL350-400. Max altitude capability was FL395. We requested reroute deviation direct OSKON A218 LUROG G7 OGETO G902 then as filed. Was immediately cleared direct OSKON; then ATC asked if we would prefer direct LUROG direct FRENK. We accepted Magadan's suggestion for reroute. There were no indications of VA penetration observed inside or outside of aircraft. Engine indications appeared normal. We advised dispatch. ATC had us radar contact entire time. Dispatch should be more closely monitoring our flight path since they dispatched us into a known area with volcanic activity. Reports received after we queried dispatch in flight included verified satellite imagery indicating presence of the ash plume. Upon notification by Magadan Control we did not visually confirm indication of the plume because of time of day (twilight) and lack of sufficient light. However; our flight was planned downwind of the eruption with the ash plume forecast to be along the route by the time we passed. I believe we should have been flight planned UPWIND of the known volcanic activity.At the very least; we should have been informed by dispatch proactively inflight of the satellite imagery showing the plume progressing along our route as a possible hazard to avoid -- dispatch has all the tools available to monitor such information. Fortunately the Magadan controller volunteered the information to the crew in time to make course changes to avoid the ash plume.


Second narrative: I was the Captain but asleep in the bunk on break. We had received the Volcanic Ash information with our flight plan and plotted the one reported area on our plotting chart. We were well north of that area so weren't concerned. Enroute; we received a PIREP from Magadan of a different volcanic ash area on our route ahead. The FO and [relief pilot] did an excellent job of coordinating with ATC and getting a reroute to the North of the area. After we were safely out of the way of the plume; they contacted dispatch to advise them. Apparently the info of it hadn't made it through the channels to where dispatch had the information and advised us. They saw no reason to wake me and briefed me when my rest break was over. I was pleased with that decision and felt they handled it expertly.


Synopsis: B777 flight crew is informed by ATC of a volcanic ash plume ahead that will require deviation to miss and the crew accepts a revised route. This particular volcanic ash plume had not been part of the Dispatch Release and the crew only became aware when informed by Magadan Control.