Irregular RPM indications on an SF340 lead to ultimate engine failure upon landing.

Narrative:

While enroute from ZZZ1 to ZZZ; I noticed the left propeller RPM gauge showing between 1;000 RPM to 1;320 RPM. All other gauges appeared normal. I also noted engine vibration was unchanged; and yaw remained steady. After reaching cruise altitude; the left propeller RPM appeared to show a normal and stable RPM. Again on descent; the left propeller RPM began to show anomalous indications and the same range noted earlier. We began the landing sequence which requires the condition levers to be placed in the 'maximum' position. It was showing anomalous readings; but did change with the change in lever position. The needle on the gauge went past the green arc. Once again; all other indications appeared normal. Engine vibrations and yaw felt normal to those configuration inputs. Upon landing (flight idle stop light illuminated); with the power lever going from flight idle to ground idle; I felt and heard a power surge from the left engine. This was followed by loss of thrust; then the engine oil pressure triple chime. We exited the runway and proceeded with the emergency non-normal checklist and taxied to the gate.

Original NASA ASRS Text

Title: Irregular RPM indications on an SF340 lead to ultimate engine failure upon landing.

Narrative: While enroute from ZZZ1 to ZZZ; I noticed the left propeller RPM gauge showing between 1;000 RPM to 1;320 RPM. All other gauges appeared normal. I also noted engine vibration was unchanged; and yaw remained steady. After reaching cruise altitude; the left propeller RPM appeared to show a normal and stable RPM. Again on descent; the left PROP RPM began to show anomalous indications and the same range noted earlier. We began the landing sequence which requires the condition levers to be placed in the 'maximum' position. It was showing anomalous readings; but did change with the change in lever position. The needle on the gauge went past the green arc. Once again; all other indications appeared normal. Engine vibrations and yaw felt normal to those configuration inputs. Upon landing (flight idle stop light illuminated); with the power lever going from flight idle to ground idle; I felt and heard a power surge from the left engine. This was followed by loss of thrust; then the engine oil pressure triple chime. We exited the runway and proceeded with the emergency non-normal checklist and taxied to the gate.

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.

Attributes
ACN	824506
Time
Date	200902
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Make Model Name	SF 340A
Operating Under FAR Part	Part 121
Flight Phase	Climb Cruise Initial Approach
Flight Plan	IFR
Component
Aircraft Component	Turbine Engine
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 6200 Flight Crew Type 4700
Events
Anomaly	Aircraft Equipment Problem Critical