Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 122; Flight Crew Total 14554; Flight Crew Type 9436
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Weight And Balance; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; General Maintenance Action
Aircraft
On climb out we got a call from the aft galley Flight Attendant smoke coming out of the ovens. I asked the IRO to run back and check out if the smoke was burning food trays or something else. When she called back all ovens were pouring out smoke and they were in the process of de-powering the galleys. I gave the aircraft to the First Officer and [requested priority handling]. Aircraft X turning back to ZZZ with an onboard fire. I got the IRO back up and we coordinated an [expedited return.] Dispatch was notified; ATC was helping us in; Flight Attendants were briefed; and passengers briefed. We completed over weight checklist and had Crash Fire Rescue in place for a long landing and possible bailout. I told the Flight Attendants to empty every Halon bottle in the airplane. Smoke dissipated but returned after 15 minutes. I took control of the aircraft and flew an overweight landing to Runway XX; rolled to the end; turned off and were greeted by Crash Fire Rescue. We were given a frequency for the fire crew and they checked us out as nominal. Since the smoke was dissipating we decided to get to the gate and let the fire crew on board.
On climb out on the SID; at approximately 12;000 ft.; we received a call from the Flight Attendants in the aft galley. They noticed that steam or smoke was coming out of 3 ovens and starting to come out a few more; as well. They could not determine the cause or type of steam/smoke and we directed them to contact the lead Flight Attendant to assist and coordinate.They were able to confirm that there was smoke coming from the aft ovens and that they were in the process of shutting off electrical power to the aft galley. At this time we were leveling off at FL310; after a brief discussion we decided the best course of action was to return to ZZZ. The Captain then [advised ATC]; stated our intentions; and started coordinating our return with ATC to go back to ZZZ for recovery. Dispatch was notified via ACARS and a SATCOM voice link of our intentions. As we continued our descent into ZZZ; we were notified by the Flight Attendants that the smoke had started to return. The Captain then directed them to open the ovens and discharge the Halon fire extinguishers into them to mitigate the smoke and extinguish the source of the smoke.Following our descent; we shot the ILS approach with an uneventful landing and roll out. We exited the end of the runway and contacted the firefighting support team to coordinate a visual check of the rear part of the aircraft for smoke or fire. Once they confirmed that no external smoke or flames were present; we proceeded to the gate with them following in support.Upon arrival at the gate; the fire fighters boarded the aircraft to confirm there was no further danger and proceeded to deplane the aircraft once getting the 'all clear'.
B777 flight crew reported a galley fire that resulted in an air return and overweight landing.