Narrative:

After pushback and engine start; flight attendant 'a' called to report several passenger and aft flight attendants stated they had noticed an 'electric burning smell' during engine start. We shut down both engines; and I personally went to the cabin to investigate. I questioned several passenger who had reported the smell. All stated the smell was transient and they could no longer detect it. I used the handset and PA to inform all passenger of the situation; and state that we would restart the engines; and if we had any more unidented smells; we would return to the gate. We restarted the engines and called flight attendant 'a' and asked if anyone could smell anything. She told us there were no unusual odors; so we taxied to runway 25. I was PF; and shortly after takeoff (approximately 2000 ft AGL) I smelled a burning odor in the cockpit. I asked the first officer if he could smell it; but he could not at first. At that moment; flight attendant 'a' called to say the odor had returned. I directed the first officer to declare an emergency and request an immediate return to ZZZ. The first officer donned his oxygen mask; but smell quickly dissipated; so I decided to discontinue smoke/fumes checklist and concentrate on flying the plane for an immediate landing. We made a left 270 degree turn and intercepted final for runway 34R at the FAF for a normal landing. We taxied off runway and stopped. We asked the crash crew to examine the exterior of the plane with emphasis on the landing gear. All appeared normal; and there were no more odors in the cabin or cockpit; so we taxied to the gate and shut down. Supplemental information from acn 792674: on the captain's order; we declared an emergency and coordinated our return to ZZZ. I donned the oxygen mask and communicated with ATC regarding souls on board; fuel and desired runway. We set the aircraft up for the return to field and completed a normal approach. On approach; the odor dissipated and after landing (approximately 80 KTS) I advised the passenger to 'remain seated.' we had the fire rescue personnel investigate the landing gear before returning to the gate. Emergency personnel noted nothing unusual so we elected to return to the gate and deplane. After completing administrative duties the captain asked the entire crew if we felt comfortable continuing on in a new aircraft. We all felt comfortable with that decision. We got a new aircraft for the flight and completed our flight uneventfully.

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Original NASA ASRS Text

Title: AN ELECTRICAL BURNING SMELL IN AN A319'S CABIN OCCURRED DURING START THEN DISSIPATED. AFTER TKOF THE SMELL RETURNED; AN EMER WAS DECLARED WITH A RETURN TO LAND.

Narrative: AFTER PUSHBACK AND ENG START; FLT ATTENDANT 'A' CALLED TO RPT SEVERAL PAX AND AFT FLT ATTENDANTS STATED THEY HAD NOTICED AN 'ELECTRIC BURNING SMELL' DURING ENG START. WE SHUT DOWN BOTH ENGS; AND I PERSONALLY WENT TO THE CABIN TO INVESTIGATE. I QUESTIONED SEVERAL PAX WHO HAD RPTED THE SMELL. ALL STATED THE SMELL WAS TRANSIENT AND THEY COULD NO LONGER DETECT IT. I USED THE HANDSET AND PA TO INFORM ALL PAX OF THE SIT; AND STATE THAT WE WOULD RESTART THE ENGS; AND IF WE HAD ANY MORE UNIDENTED SMELLS; WE WOULD RETURN TO THE GATE. WE RESTARTED THE ENGS AND CALLED FLT ATTENDANT 'A' AND ASKED IF ANYONE COULD SMELL ANYTHING. SHE TOLD US THERE WERE NO UNUSUAL ODORS; SO WE TAXIED TO RWY 25. I WAS PF; AND SHORTLY AFTER TKOF (APPROX 2000 FT AGL) I SMELLED A BURNING ODOR IN THE COCKPIT. I ASKED THE FO IF HE COULD SMELL IT; BUT HE COULD NOT AT FIRST. AT THAT MOMENT; FLT ATTENDANT 'A' CALLED TO SAY THE ODOR HAD RETURNED. I DIRECTED THE FO TO DECLARE AN EMER AND REQUEST AN IMMEDIATE RETURN TO ZZZ. THE FO DONNED HIS OXYGEN MASK; BUT SMELL QUICKLY DISSIPATED; SO I DECIDED TO DISCONTINUE SMOKE/FUMES CHKLIST AND CONCENTRATE ON FLYING THE PLANE FOR AN IMMEDIATE LNDG. WE MADE A L 270 DEG TURN AND INTERCEPTED FINAL FOR RWY 34R AT THE FAF FOR A NORMAL LNDG. WE TAXIED OFF RWY AND STOPPED. WE ASKED THE CRASH CREW TO EXAMINE THE EXTERIOR OF THE PLANE WITH EMPHASIS ON THE LNDG GEAR. ALL APPEARED NORMAL; AND THERE WERE NO MORE ODORS IN THE CABIN OR COCKPIT; SO WE TAXIED TO THE GATE AND SHUT DOWN. SUPPLEMENTAL INFO FROM ACN 792674: ON THE CAPT'S ORDER; WE DECLARED AN EMER AND COORDINATED OUR RETURN TO ZZZ. I DONNED THE OXYGEN MASK AND COMMUNICATED WITH ATC REGARDING SOULS ON BOARD; FUEL AND DESIRED RWY. WE SET THE ACFT UP FOR THE RETURN TO FIELD AND COMPLETED A NORMAL APCH. ON APCH; THE ODOR DISSIPATED AND AFTER LNDG (APPROX 80 KTS) I ADVISED THE PAX TO 'REMAIN SEATED.' WE HAD THE FIRE RESCUE PERSONNEL INVESTIGATE THE LNDG GEAR BEFORE RETURNING TO THE GATE. EMER PERSONNEL NOTED NOTHING UNUSUAL SO WE ELECTED TO RETURN TO THE GATE AND DEPLANE. AFTER COMPLETING ADMINISTRATIVE DUTIES THE CAPT ASKED THE ENTIRE CREW IF WE FELT COMFORTABLE CONTINUING ON IN A NEW ACFT. WE ALL FELT COMFORTABLE WITH THAT DECISION. WE GOT A NEW ACFT FOR THE FLT AND COMPLETED OUR FLT UNEVENTFULLY.

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.