Date: 201710
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Galley Furnishing
Component problem: Malfunctioning; Failed
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Time Pressure
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Overcame Equipment Problem; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: While eastbound cruising at FL260; approximately 100 miles from ZZZ; I received a call from the aft galley that there was fire in one of the ovens. The Flight Attendant said they would fight the fire and would call back. Within a few seconds they called the Captain who spoke to the Flight Attendants. He told me that the Flight Attendant said power had been removed from the oven and the fire had been contained in the oven. They also said the wall was very hot. The Captain also said the Flight Attendant said there was smoke; but it had dissipated. The Flight Attendant called back again and told the Captain there was no fire or smoke now; but the passengers' meals were ruined. After that call; the Captain and I ran an un-annunciated checklist. We ran the checklist with first; the understanding that the power to the oven had been removed and second; under the impression that currently there was no longer smoke; fire; or fumes.Very shortly; if not immediately after completing the checklist; the Flight Attendant called back up and said the wall and oven were very; very hot. With that information; the Captain asked that the flying copilot be woken from break and to come to the cockpit. The flying copilot came to the cockpit to get a quick briefing. The Captain updated him and asked that he go back to the aft galley to assess the situation. Shortly thereafter; the flying copilot called the Captain and said the wall was very hot and recommended we land. The Captain hung up the phone; said he had the aircraft; and told me to advise ATC that we needed an immediate divert. I made a call requesting the diversion for a fire in the back of the aircraft and advised [ATC]. I also requested firefighting and rescue crews be there for arrival. Immediately; ATC gave us clearance to ZZZ via an initial heading (270?) and an initial descent (15;000) with the local altimeter setting. Shortly after passing FL180; the flying copilot came to the cockpit. I let him in and he took his seat.The Captain and flying copilot took over the radios and flying duties while I coordinated with the Flight Attendant and made a PA to the passengers about the diversion. The Captain continued to fly as the flying First Officer briefed an approach and landing which he would fly for the ILS. Once the brief was complete; they completed the approach descent checklist. In my coordination with the Flight Attendants; I told them it would be 10-15 minutes before landing; with fire and rescue crews standing by. While still descending; the Captain directed me to give a quick call to Dispatch to advise them of our divert and to ask them to coordinate with operations. After that was completed; two more calls came from the Flight Attendants in the back saying the oven wall was still very hot and there was some lingering smoke. I told the Captain about the hot wall and he asked for a high speed descent to expedite the arrival. ATC granted that request. ATC gave us continuing descents to approach altitude and vectors for an ILS. Captain had me look up and provide him with the runway length as we did not have time to get landing performance data via ACARS. While being vectored; I next pulled up the reference guide for diversions to make sure we had all the bases covered; which we did. Next; at approximately 25 miles out; I told the Flight Attendants we would be on the ground in 8 minutes. Intercepting final I made a PA to the Flight Attendants we would be landing in 3 minutes. This call and PA were provided to the Flight Attendants because they had carts; trays; meals; drinks; etc. to pick up and I wanted them to be in their seats prior to landing.The approach and landing were uneventful. On rollout; the passengers were told to remain seated. We stopped on the runway; set the brakes; and shut the engines down. The Flight Attendants called and said there was no smoke or fire; but the wall was still hot. With that information; we ran the [appropriate] checklist one more time. After that; the after landing flows were completed along with the parking checklist. Additionally; the reference guide diversion recovery checklist was reviewed. Fire crews came on board and determined the fire was out and was contained in the oven; which was still hot. Lastly; maintenance came on the aircraft and removed the oven before we were towed to the gate.


Second narrative: [Report narrative contained no additional information.]


Synopsis: B777 flight crew reported that during cruise flight an oven in the aft galley was on fire.