The smoke alarm in a B757-200's lav by door 2L sounded after takeoff. An emergency was declared with...

Attributes
ACN	809103
Time
Date	200810
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 17000
Environment
Flight Conditions	IMC
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 150 flight time total : 21000 flight time type : 3100
ASRS Report	809103
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 70 flight time total : 13000 flight time type : 50
ASRS Report	809107
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : diverted to another airport
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We departed ZZZ on runway 8 and the first officer was the PF. As we passed through 17000 ft; I received a call from the flight attendant at the mid cabin. She reported that the smoke alarm was going off in the lavatory by door 2L. I asked her to check and see if she could determine the cause. She called back very shortly and said that she could see no smoke but could smell electrical odor in the lavatory and for several rows around the lavatory. I declared an emergency with ATC and requested an immediate return to ZZZ. I talked to dispatch and requested to have the emergency equipment standing by for our arrival in ZZZ. We received another call from the flight attendant on the way back to ZZZ and she reported that the alarm had stopped but she could still smell the odor. We advised the purser that a cabin preparation was not necessary but to let us know if the situation deteriorated. The smoke alarm did come on again prior to landing and stopped before we arrived at the gate. The first officer made a normal approach and landing. The emergency equipment followed us to the gate and the fire personnel boarded the aircraft and found no apparent sign of fire by the time we left the aircraft.

Original NASA ASRS Text

Title: THE SMOKE ALARM IN A B757-200'S LAV BY DOOR 2L SOUNDED AFTER TKOF. AN EMER WAS DECLARED WITH A RETURNED TO LAND. AN ELECTRICAL SMELL WAS PRESENT.

Narrative: WE DEPARTED ZZZ ON RWY 8 AND THE FO WAS THE PF. AS WE PASSED THROUGH 17000 FT; I RECEIVED A CALL FROM THE FLT ATTENDANT AT THE MID CABIN. SHE RPTED THAT THE SMOKE ALARM WAS GOING OFF IN THE LAVATORY BY DOOR 2L. I ASKED HER TO CHK AND SEE IF SHE COULD DETERMINE THE CAUSE. SHE CALLED BACK VERY SHORTLY AND SAID THAT SHE COULD SEE NO SMOKE BUT COULD SMELL ELECTRICAL ODOR IN THE LAVATORY AND FOR SEVERAL ROWS AROUND THE LAVATORY. I DECLARED AN EMER WITH ATC AND REQUESTED AN IMMEDIATE RETURN TO ZZZ. I TALKED TO DISPATCH AND REQUESTED TO HAVE THE EMER EQUIP STANDING BY FOR OUR ARR IN ZZZ. WE RECEIVED ANOTHER CALL FROM THE FLT ATTENDANT ON THE WAY BACK TO ZZZ AND SHE RPTED THAT THE ALARM HAD STOPPED BUT SHE COULD STILL SMELL THE ODOR. WE ADVISED THE PURSER THAT A CABIN PREPARATION WAS NOT NECESSARY BUT TO LET US KNOW IF THE SITUATION DETERIORATED. THE SMOKE ALARM DID COME ON AGAIN PRIOR TO LNDG AND STOPPED BEFORE WE ARRIVED AT THE GATE. THE FO MADE A NORMAL APCH AND LNDG. THE EMER EQUIP FOLLOWED US TO THE GATE AND THE FIRE PERSONNEL BOARDED THE ACFT AND FOUND NO APPARENT SIGN OF FIRE BY THE TIME WE LEFT THE ACFT.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

The smoke alarm in a B757-200's lav by door 2L sounded after takeoff. An emergency was declared with a returned to land. An electrical smell was present.