Date: 201509
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737 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
Reporter organization: Air Carrier
Reporter function: Captain
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: While cruising at FL340 the B Flight Attendant called the flight deck and reported the aft lavatory smoke alarm was going off and there was a burnt electrical smell coming from the same area. We immediately donned our oxygen masks and established communications. In rapid succession we determined our location; the nearest airport; and told Center we needed to divert immediately. Center coordinated our turn to [divert airport] and descent with other aircraft in the area and we started down. We started the Smoke; Fire and Fumes Checklist in the QRH. The Captain flew the aircraft while the First Officer (FO) completed the checklist and communicated with the Flight Attendants. The Flight Attendants communicated with the Passengers about what was occurring. We [flew a] visual approach. We turned off the runway and had the Fire Department check the aircraft for any signs of a fire. The Captain made an announcement to the people about what was happening and what would happen next. The Fire Department determined there were no signs of a fire and cleared us to taxi to the gate. The FO called Ops to get a gate and we proceeded to the gate after receiving clearance from Ground Control. Once at the gate the Fire Department came onto the aircraft and checked for any signs of a fire. Once that was complete and the passengers were deplaned we called Dispatch and then Contract Maintenance. Upon talking with the Flight Attendants on the ground; the burnt electrical smell was evident anytime the aft closet was opened. Also; we learned the Flight Attendants searched through all of the trash and compartments looking for a fire source but did not find anything. The circuit breaker to the smoke detector was pulled once we were on the ground and cancelled the alarm. Contract Maintenance reset the circuit breaker and the alarm did not continue. The Contract Maintainer did not notice a burnt electrical smell until several of the ceiling panels in the aft galley were removed and he investigated in the ceiling area. The aircraft was turned over to Maintenance at this point to determine the issue. It was only 15 minutes from the time the alarm was reported to the time we landed. In that time we started the QRH Checklist and the FO reviewed all the items but there was not enough time to fully and completely finish the Smoke; Fire and Fumes Checklist. Trying to complete that checklist while trying to coordinate with ATC; change destination; get ATIS; set up approach; complete normal descent and approach checklist and communicate with the cabin just was not possible in that short a time.




Synopsis: A B737 Captain reported diverting to a nearby airport after a burning electrical smell was reported by a Flight Attendant.