Narrative:

On decent the captain; who was pilot flying at the time; reduced the power levers per ATC request to begin slowing. When the power levers were reduced the right engine torque was not responsive with the power lever adjustments. The torque stayed at a constant 80% and could not be adjusted. The captain then transfered controls to the first officer in order to troubleshoot the problem and speak with company. We spoke to maintenance and decided to run the erratic/uncommanded engine operation checklist on the qrc. After running that checklist we were still unable to control the power on our right engine; which remained at 80%. We then decided that we were going to have to shut the engine down. We declared the emergency at this point to ATC. I advised the passengers and the flight attendant that the right engine would be shut down and reassured them it was something we practice all the time in training. The first officer and I discussed our plan of action and decided that we would get established on the approach to the runway and then shut down the engine via the checklist about 20 miles out. The first officer was the pilot flying and the captain was pilot not flying at this point. At 23 miles out on the approach we ran the engine shutdown checklist and shutdown the engine. We landed single engine with no other abnormal events and taxied to the gate. We later learned a bolt sheared off the back of the hydro-mechanical metering unit and disconnected our control of the power on the right engine.

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Original NASA ASRS Text

Title: An SF340 flight crew had to shut down one engine for landing when it failed to respond to thrust lever inputs and remained at excessively high torque levels for the approach and landing.

Narrative: On decent the Captain; who was pilot flying at the time; reduced the power levers per ATC request to begin slowing. When the power levers were reduced the right engine torque was not responsive with the power lever adjustments. The torque stayed at a constant 80% and could not be adjusted. The Captain then transfered controls to the First Officer in order to troubleshoot the problem and speak with Company. We spoke to Maintenance and decided to run the Erratic/Uncommanded Engine Operation Checklist on the QRC. After running that checklist we were still unable to control the power on our right engine; which remained at 80%. We then decided that we were going to have to shut the engine down. We declared the emergency at this point to ATC. I advised the passengers and the Flight Attendant that the right engine would be shut down and reassured them it was something we practice all the time in training. The First Officer and I discussed our plan of action and decided that we would get established on the approach to the runway and then shut down the engine via the checklist about 20 miles out. The First Officer was the pilot flying and the Captain was pilot not flying at this point. At 23 miles out on the approach we ran the engine shutdown checklist and shutdown the engine. We landed single engine with no other abnormal events and taxied to the gate. We later learned a bolt sheared off the back of the Hydro-Mechanical Metering Unit and disconnected our control of the power on the right engine.

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.