Narrative:

5 mins after departing dulles int'l airport (iad) I noticed that the left #1 engine began displaying erratic egt, torque, and RPM indications, which were accompanied by an associated yawing of the aircraft. I elected to return for landing, and instructed the first officer to notify the company, as I began troubleshooting the problem. Recalling that during climbout, all engine parameters of operation were well within prescribed limitations, I began implementing the approved troubleshooting procedure for erratic engine performance: move the RPM levers fully forward, which I did, retard the power on the affected engine to assure both egt and torque are both below limits, again which I did, at this point, the erratic operation had ceased, and I had discontinued the procedure, believing I had solved the problem. Switch off the propeller sync (not applicable, since this aircraft's system had been disconnected), switch off the ttl computer on the affected engine, which I did not do, reasoning that previous action had adequately solved the problem. About a minute later, as I am turning final, the left engine again began performing erratically, and I felt it appropriate to secure the engine, perform appropriate checklists, and continue with the approach, as opposed to abandoning the approach and continue to troubleshoot the errant engine. WX at dulles was 300 overcast and 1 1/2 mi visibility, and I felt highly confident that safety was assured with my decision. The approach, landing, and taxi were all uneventful. Contributing factors leading to the in-flight engine shutdown were: flight crew - not completing the full troubleshooting procedure when the problem first presented itself, company - quality of maintenance at this cash-strapped is suspect. Employee attrition is high, manufacturer - the ttl system is proving to be of dubious value, should be removed, and full authority for engine management returned to the flight crew.

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Original NASA ASRS Text

Title: COMMUTER LTT DEVELOPED ENGINE PROBLEMS DURING CLIMB OUT FROM IAD. RETURN LAND.

Narrative: 5 MINS AFTER DEPARTING DULLES INT'L ARPT (IAD) I NOTICED THAT THE LEFT #1 ENGINE BEGAN DISPLAYING ERRATIC EGT, TORQUE, AND RPM INDICATIONS, WHICH WERE ACCOMPANIED BY AN ASSOCIATED YAWING OF THE ACFT. I ELECTED TO RETURN FOR LNDG, AND INSTRUCTED THE F/O TO NOTIFY THE COMPANY, AS I BEGAN TROUBLESHOOTING THE PROBLEM. RECALLING THAT DURING CLIMBOUT, ALL ENGINE PARAMETERS OF OPERATION WERE WELL WITHIN PRESCRIBED LIMITATIONS, I BEGAN IMPLEMENTING THE APPROVED TROUBLESHOOTING PROC FOR ERRATIC ENGINE PERFORMANCE: MOVE THE RPM LEVERS FULLY FORWARD, WHICH I DID, RETARD THE POWER ON THE AFFECTED ENGINE TO ASSURE BOTH EGT AND TORQUE ARE BOTH BELOW LIMITS, AGAIN WHICH I DID, AT THIS POINT, THE ERRATIC OPERATION HAD CEASED, AND I HAD DISCONTINUED THE PROC, BELIEVING I HAD SOLVED THE PROBLEM. SWITCH OFF THE PROPELLER SYNC (NOT APPLICABLE, SINCE THIS ACFT'S SYSTEM HAD BEEN DISCONNECTED), SWITCH OFF THE TTL COMPUTER ON THE AFFECTED ENGINE, WHICH I DID NOT DO, REASONING THAT PREVIOUS ACTION HAD ADEQUATELY SOLVED THE PROBLEM. ABOUT A MINUTE LATER, AS I AM TURNING FINAL, THE LEFT ENGINE AGAIN BEGAN PERFORMING ERRATICALLY, AND I FELT IT APPROPRIATE TO SECURE THE ENGINE, PERFORM APPROPRIATE CHECKLISTS, AND CONTINUE WITH THE APCH, AS OPPOSED TO ABANDONING THE APCH AND CONTINUE TO TROUBLESHOOT THE ERRANT ENGINE. WX AT DULLES WAS 300 OVCST AND 1 1/2 MI VISIBILITY, AND I FELT HIGHLY CONFIDENT THAT SAFETY WAS ASSURED WITH MY DECISION. THE APCH, LNDG, AND TAXI WERE ALL UNEVENTFUL. CONTRIBUTING FACTORS LEADING TO THE INFLT ENGINE SHUTDOWN WERE: FLT CREW - NOT COMPLETING THE FULL TROUBLESHOOTING PROC WHEN THE PROBLEM FIRST PRESENTED ITSELF, COMPANY - QUALITY OF MAINT AT THIS CASH-STRAPPED IS SUSPECT. EMPLOYEE ATTRITION IS HIGH, MANUFACTURER - THE TTL SYSTEM IS PROVING TO BE OF DUBIOUS VALUE, SHOULD BE REMOVED, AND FULL AUTHORITY FOR ENGINE MGMNT RETURNED TO THE FLT CREW.

Data retrieved from NASA's ASRS site as of August 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.