Narrative:

En route at cruise on our #1 engine we started to encounter intermittent engine electronic control unit faults resulting in power surges. At the same time on our #2 engine, we were receiving faulty torque gauge indications (ie, fluctuations +/-50% torque) with no real torque surges, however, we decided the best course of action would be to abandon going to our scheduled destination of lse and divert to msn. We continued then to msn and advised ATC that we were not declaring an emergency but doing a precautionary landing. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was an ATR42 with PW127E engines with electronic fuel control. The reporter said the #1 engine was surging with the electronic fuel control 'on' or 'off' and the #2 engine had intermittent and erratic indications of +/-50% torque fluctuations with no real fluctuations. The reporter said that on the ground maintenance cleaned all electrical connectors on the electronic fuel control units and the #2 engine torque transmitter. The reporter stated that maintenance then ran the engines with the reporter present for better than 1 hour and could not duplicate the report. The reporter said the aircraft was returned to service and operated normally the remainder of the day.

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Original NASA ASRS Text

Title: AN ATR42 IN CRUISE AT 14000 FT DIVERTED DUE TO #1 ENG PWR SURGING AND #2 ENG TORQUE INDICATIONS ERRATIC.

Narrative: ENRTE AT CRUISE ON OUR #1 ENG WE STARTED TO ENCOUNTER INTERMITTENT ENG ELECTRONIC CTL UNIT FAULTS RESULTING IN PWR SURGES. AT THE SAME TIME ON OUR #2 ENG, WE WERE RECEIVING FAULTY TORQUE GAUGE INDICATIONS (IE, FLUCTUATIONS +/-50% TORQUE) WITH NO REAL TORQUE SURGES, HOWEVER, WE DECIDED THE BEST COURSE OF ACTION WOULD BE TO ABANDON GOING TO OUR SCHEDULED DEST OF LSE AND DIVERT TO MSN. WE CONTINUED THEN TO MSN AND ADVISED ATC THAT WE WERE NOT DECLARING AN EMER BUT DOING A PRECAUTIONARY LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS AN ATR42 WITH PW127E ENGS WITH ELECTRONIC FUEL CTL. THE RPTR SAID THE #1 ENG WAS SURGING WITH THE ELECTRONIC FUEL CTL 'ON' OR 'OFF' AND THE #2 ENG HAD INTERMITTENT AND ERRATIC INDICATIONS OF +/-50% TORQUE FLUCTUATIONS WITH NO REAL FLUCTUATIONS. THE RPTR SAID THAT ON THE GND MAINT CLEANED ALL ELECTRICAL CONNECTORS ON THE ELECTRONIC FUEL CTL UNITS AND THE #2 ENG TORQUE XMITTER. THE RPTR STATED THAT MAINT THEN RAN THE ENGS WITH THE RPTR PRESENT FOR BETTER THAN 1 HR AND COULD NOT DUPLICATE THE RPT. THE RPTR SAID THE ACFT WAS RETURNED TO SVC AND OPERATED NORMALLY THE REMAINDER OF THE DAY.

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.