Narrative:

At cruise left engine EPR exceeded upper limit. While trying to correct problem by throttling back; the autothrottles kept reengaging to advance power. We disconnected autothrottle system and were not able to regain control of the engine. It was either greater than maximum limit EPR thrust or flight idle. I declared an emergency not knowing if the engine would fail to produce thrust at the lower power setting. As long as the engine was producing thrust and not exceeding limitations I saw no reason to shut the engine down. The approach and landing were uneventful. We had arff standing by and they followed us to the gate without further incident.

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Original NASA ASRS Text

Title: A B757-200 FLT CREW LOST THROTTLE CONTROL OF THEIR L ENG; RESULTING IN A CHOICE OF MAX THRUST OR IDLE THRUST. THE CREW DECLARED AN EMERGENCY AND LANDED UNEVENTFULLY.

Narrative: AT CRUISE L ENG EPR EXCEEDED UPPER LIMIT. WHILE TRYING TO CORRECT PROB BY THROTTLING BACK; THE AUTOTHROTTLES KEPT REENGAGING TO ADVANCE PWR. WE DISCONNECTED AUTOTHROTTLE SYS AND WERE NOT ABLE TO REGAIN CTL OF THE ENG. IT WAS EITHER GREATER THAN MAX LIMIT EPR THRUST OR FLT IDLE. I DECLARED AN EMER NOT KNOWING IF THE ENG WOULD FAIL TO PRODUCE THRUST AT THE LOWER PWR SETTING. AS LONG AS THE ENG WAS PRODUCING THRUST AND NOT EXCEEDING LIMITATIONS I SAW NO REASON TO SHUT THE ENG DOWN. THE APCH AND LNDG WERE UNEVENTFUL. WE HAD ARFF STANDING BY AND THEY FOLLOWED US TO THE GATE WITHOUT FURTHER INCIDENT.

Data retrieved from NASA's ASRS site as of January 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.