Narrative:

Approximately 35 mins into the flight after leveling off at our cruising altitude and setting cruise power, we began to experience problems with the left engine. The left engine began a slow acceleration to 100% torque and 100% RPM. I reduced the power lever for the engine. This seemed to relieve the problem. After an additional 5 mins the engine again accelerated to 100% torque and 100% RPM. At this time we decided to return to republic airport and requested vectors to republic. Our left engine power lever was at flight idle yet we were still getting 100% power. Due to WX considerations, I decided to match the power and continued to observe the left engine while returning to republic airport. When we were within 10 NM of republic airport, I requested that the equipment be in place in the event we would need assistance. Shortly after requesting the equipment be called, the oil pressure on the left engine began to fluctuate and I observed the governor's controling the power on the left engine as power and oil pressure began to rise and fall. At this time, I decided that once established on the ILS to runway 14 we would perform a precautionary shutdown as I could no longer predict the power settings for the left engine. We continued the ILS to runway 14 with no incident and performed a normal single engine landing. At no time were my passenger alarmed or concerned for their safety. We later changed aircraft to abc and continued the charter flight. At no time did I consider the flight to be in significant danger as to require an immediate landing. Callback conversation with reporter revealed the following information: the reporter stated the cause of the loss of engine control was a failed engine torque transducer. The reporter said maintenance was able to prove the fix with an engine run after the transducer was replaced.

Related reports:

Google
 

Original NASA ASRS Text

Title: A BAE3100 IN CRUISE AT 9000 FT DECLARED AN EMER AND DIVERTED DUE TO LOSS OF ENG CTL CAUSED BY A FAILED ENG TORQUE TRANSDUCER.

Narrative: APPROX 35 MINS INTO THE FLT AFTER LEVELING OFF AT OUR CRUISING ALT AND SETTING CRUISE PWR, WE BEGAN TO EXPERIENCE PROBS WITH THE L ENG. THE L ENG BEGAN A SLOW ACCELERATION TO 100% TORQUE AND 100% RPM. I REDUCED THE PWR LEVER FOR THE ENG. THIS SEEMED TO RELIEVE THE PROB. AFTER AN ADDITIONAL 5 MINS THE ENG AGAIN ACCELERATED TO 100% TORQUE AND 100% RPM. AT THIS TIME WE DECIDED TO RETURN TO REPUBLIC ARPT AND REQUESTED VECTORS TO REPUBLIC. OUR L ENG PWR LEVER WAS AT FLT IDLE YET WE WERE STILL GETTING 100% PWR. DUE TO WX CONSIDERATIONS, I DECIDED TO MATCH THE PWR AND CONTINUED TO OBSERVE THE L ENG WHILE RETURNING TO REPUBLIC ARPT. WHEN WE WERE WITHIN 10 NM OF REPUBLIC ARPT, I REQUESTED THAT THE EQUIP BE IN PLACE IN THE EVENT WE WOULD NEED ASSISTANCE. SHORTLY AFTER REQUESTING THE EQUIP BE CALLED, THE OIL PRESSURE ON THE L ENG BEGAN TO FLUCTUATE AND I OBSERVED THE GOVERNOR'S CTLING THE PWR ON THE L ENG AS PWR AND OIL PRESSURE BEGAN TO RISE AND FALL. AT THIS TIME, I DECIDED THAT ONCE ESTABLISHED ON THE ILS TO RWY 14 WE WOULD PERFORM A PRECAUTIONARY SHUTDOWN AS I COULD NO LONGER PREDICT THE PWR SETTINGS FOR THE L ENG. WE CONTINUED THE ILS TO RWY 14 WITH NO INCIDENT AND PERFORMED A NORMAL SINGLE ENG LNDG. AT NO TIME WERE MY PAX ALARMED OR CONCERNED FOR THEIR SAFETY. WE LATER CHANGED ACFT TO ABC AND CONTINUED THE CHARTER FLT. AT NO TIME DID I CONSIDER THE FLT TO BE IN SIGNIFICANT DANGER AS TO REQUIRE AN IMMEDIATE LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE LOSS OF ENG CTL WAS A FAILED ENG TORQUE TRANSDUCER. THE RPTR SAID MAINT WAS ABLE TO PROVE THE FIX WITH AN ENG RUN AFTER THE TRANSDUCER WAS REPLACED.

Data retrieved from NASA's ASRS site as of July 2007 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.