Date: 201403
Local time of day: 0001-0600
Location: ZZZ.ARTCC, US
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Galley Furnishing
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Other / Unknown; Situational Awareness
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Overcame Equipment Problem; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: The flight attendants reported that they had a possible fire in the aft galley. An oven which had been turned off for about 45 minutes was found to be very hot and there was a faint electrical odor. There was no smoke. She asked permission to pull the circuit breakers in the aft galley and I said yes. I said that the oven should cool down slowly once power was removed but to keep me informed. A few minutes later the Flight Attendant informed me that when they opened the oven door; the oven was found to be glowing red hot on the side panel holes and was emitting intense heat. One Flight Attendant donned a PBE and discharged one Halon fire extinguisher into the oven; as it did not seem to be cooling down. I was the pilot flying and at this point I directed the First Officer to run the QRC/QRH for Smoke Fumes or Fire in the Cabin. At this time I also overheard a Flight Attendant making a PA about these unusual activities in the aft galley and I immediately followed it up with my own PA. At this point I told the passengers that the flight attendants had dealt with an oven overheat and that power was removed and the situation was stable and we would be watching it closely. On the flight deck the First Officer had gotten down to step 11 on the QRH. Galley power was off. Just a few minutes later; the Flight Attendant informed me that the oven did not seem to be cooling down and the adjacent bins also seemed quite warm. There was clearly concern in her voice. We decided that the second choice of step 11 was appropriate: We proceeded down that path which involved diverting to the nearest suitable airport. I informed the Flight Attendant that we would divert to ZZZ and she seemed relieved. Although we were just north of ZZZ1 and about 110 miles south of ZZZ; we were at 40;000 FT and were at the perfect distance to accomplish our descent; giving us time to finish the QRH and adequately prepare for the approach. The winds at ZZZ favored landing to the north (straight ahead). It was very simple to continue straight ahead and begin a normal descent. Landing at ZZZ1 would have required a higher workload due to the extra maneuvering that would have been required and a more difficult energy management task. It would not have been any quicker unless we did an emergency descent profile which I did not feel was appropriate. Once the decision to divert was made; I had the First Officer complete the QRH and start building the approach in ZZZ. I declared an emergency with Center; using the words galley oven fire; gave them our souls on board and fuel; and our intention to divert to ZZZ. I asked Center to inform our company Dispatch of our emergency and intention to divert. I made a second PA informing the passengers that although the situation with the oven seemed stable; the oven was not cooling down as fast as we would like; and the safe course of action was to divert to ZZZ (words to that effect). During the 20 minutes or so it took to get to the airport; the fumes and heat dissipated gradually and we decided that a normal taxi to the gate and deplaning was appropriate. We so informed ATC that we did not anticipate any evacuation and intended to taxi to the gate.During the descent; Dispatch called us and I talked to them briefly about our situation and intentions. Dispatch sent an amended release via ACARS for the divert to ZZZ. RNAV GPS Y Runway 34L approach; with field in sight 15 miles out. Passengers deplaned; all seemed in good spirits. No smoke in the cabin; no injuries. Passengers remained calm the entire time. I made another PA in the gate area to thank the passengers for their patience and understanding; and informed them of the plan to fly in replacement aircraft. I offered to answer questions that anyone might have as soon as I completed required paperwork and phone reports. The First Officer remained in the gate area talking to passengers while I went back to the aircraft. I wrote up three discrepancies in the logbook; the oven overheat; the use of the PBE and the use of the Halon fire extinguisher. Mechanics flew in and about 2 hours after landing; found the oven controller to still be quite warm. Mechanics found no damage to any structure or wiring; suspecting a runaway controller. FAA Maintenance Inspector arrived about the same time the mechanics did and questioned the crew and the mechanics inspected the galley oven briefly. He asked for and was provided copies of all Maintenance logbook write-ups; and the Maintenance Ferry Permit which we provided to him. He commented that he thought we did everything right. Mechanics' initial assessment was a runaway oven controller (thermostat).




Synopsis: B737-700 Captain is informed of a runaway oven in the aft galley by flight attendants requesting permission to pull circuit breakers; which is granted. The oven does not appear to be cooling down and a halon fire extinguisher is discharged into the oven and the crew elects to run the QRH for smoke or fire that cannot be extinguished quickly and divert to a suitable airport.