Narrative:

Smelled burning electrical smell in cockpit; also was experienced throughout the cabin. Oxygen masked donned by cockpit crew; smoke/fire/fumes qrc performed. The odor did not diminish; nor could the source be determined. Emergency was declared; flight attendants told to do a cabin advisory; dispatch was notified; passengers informed. Then the flight was diverted to the nearest suitable airport and landed without further incident.

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Original NASA ASRS Text

Title: A B757 flight crew experienced a burning electrical smell of unknown origin in-flight; declared an emergency; and diverted to the nearest suitable airport.

Narrative: Smelled burning electrical smell in cockpit; also was experienced throughout the cabin. Oxygen masked donned by cockpit crew; smoke/fire/fumes QRC performed. The odor did not diminish; nor could the source be determined. Emergency was declared; flight attendants told to do a cabin advisory; Dispatch was notified; passengers informed. Then the flight was diverted to the nearest suitable airport and landed without further incident.

Data retrieved from NASA's ASRS site as of April 2012 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.