Narrative:

Turning final and cleared visual approach; I was about to question the captain why he was starting to fly high on the GS when he commented and made question about the left engine not operating normally. Upon observing; it did appear that the left engine was still producing a great amount of thrust at flight idle. We elected to shut the engine down and go-around. It was an uneventful go-around; declared an emergency; and took a turn to the east. On the vector with the aircraft stable and safe; we decided; after observing restart parameters; to attempt to restart; which was successful. We reviewed checklists single engine and missed approach procedures and was vectored back for an uneventful 2 engine landing and taxi to the gate. Make note that there was no time where I was in question of the safety of the flight.

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Original NASA ASRS Text

Title: B757 flight crew reports left engine would not reduce to idle thrust during approach. Go-around is initiated and engine is shut down and then restarted. A normal two engine landing ensues.

Narrative: Turning final and cleared visual approach; I was about to question the Captain why he was starting to fly high on the GS when he commented and made question about the left engine not operating normally. Upon observing; it did appear that the left engine was still producing a great amount of thrust at flight idle. We elected to shut the engine down and go-around. It was an uneventful go-around; declared an emergency; and took a turn to the east. On the vector with the aircraft stable and safe; we decided; after observing restart parameters; to attempt to restart; which was successful. We reviewed checklists single engine and missed approach procedures and was vectored back for an uneventful 2 engine landing and taxi to the gate. Make note that there was no time where I was in question of the safety of the flight.

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.