B757 flight crew reported the left engine performed at a degraded rate during descent and landing.

Attributes
ACN	1576345
Time
Date	201809
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZZ.ARTCC
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Turbine Engine
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 214 Flight Crew Total 24415 Flight Crew Type 7721
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 714 Flight Crew Type 524
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Just prior to the top of descent the left engine thrust degraded slightly; rolling back from approximately 1.6 EPR to 1.4 EPR. The other engine parameters were similarly degraded. No vibration was present. We ran the engine indication fluctuation checklist and this seemed to stabilize the engine somewhat. We were well into the descent now and discussed the issue with the crew. We briefed the single engine approach and missed approach procedures and performance in case they were needed. When we leveled briefly at 3000 feet on the downwind and increased power the left engine did not respond normally. It seemed to be slightly more degraded than at cruise. I chose to keep it running since we were getting thrust from the engine. The approach to runway xx was under VMC conditions and we continued to a normal landing. We did not receive any special handling from ATC. After block in I made a maintenance logbook entry and spoke with [maintenance control].

Original NASA ASRS Text

Title: B757 flight crew reported the left engine performed at a degraded rate during descent and landing.

Narrative: Just prior to the top of descent the left engine thrust degraded slightly; rolling back from approximately 1.6 EPR to 1.4 EPR. The other engine parameters were similarly degraded. No vibration was present. We ran the Engine Indication Fluctuation checklist and this seemed to stabilize the engine somewhat. We were well into the descent now and discussed the issue with the crew. We briefed the single engine approach and missed approach procedures and performance in case they were needed. When we leveled briefly at 3000 feet on the downwind and increased power the left engine did not respond normally. It seemed to be slightly more degraded than at cruise. I chose to keep it running since we were getting thrust from the engine. The approach to Runway XX was under VMC conditions and we continued to a normal landing. We did not receive any special handling from ATC. After block in I made a maintenance logbook entry and spoke with [Maintenance control].

Data retrieved from NASA's ASRS site 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.