Narrative:

On 1/wed/88 I was the captain on flight pdx-sea. We had brought the aircraft in from den a half hour earlier. The flight from den pdx was completely uneventful and no deviation from SOP was noted. On the next leg to sea, I was flying the aircraft and a standard takeoff was accomplished. At approximately 5000' after takeoff I selected engine anti-ice on since the temperature was approximately 3 degrees C and we were about to enter the cloud bases on our climb out of pdx. Approximately 5 min later we were level at our initial climb altitude of 9000' and I observed that the right engine EPR was approximately 15 lower than the left engine. When I advanced the right engine to match EPR's, I observed that the throttle was ahead of the left engine throttle and that the right N1 N2 and egt were also higher than the left engine. At that time I suspected engine icing had occurred and matched the engines N1 and N2 tachs for power information. Approximately 5 min later, and 10 min from sea, I observed that both EPR's, N1 and N2, tachs had returned to a normal matched condition and that no engine discrepancies were noted. The approach was flown with engine anti-ice on with no problems noted. On landing and turning off the engine anti-ice, both engine EPR's and all parameters were normal. No log book entries were made. I informed the outbnd crew of the difference in EPR's and advised them of suspected engine icing and the normal readings, prior to landing, and taxiing in. The next morning we were informed that the same aircraft had an air return shortly after takeoff from sea.

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Original NASA ASRS Text

Title: ACR MLG ENGINE ANTI-ICE PROBLEM.

Narrative: ON 1/WED/88 I WAS THE CAPT ON FLT PDX-SEA. WE HAD BROUGHT THE ACFT IN FROM DEN A HALF HOUR EARLIER. THE FLT FROM DEN PDX WAS COMPLETELY UNEVENTFUL AND NO DEVIATION FROM SOP WAS NOTED. ON THE NEXT LEG TO SEA, I WAS FLYING THE ACFT AND A STANDARD TKOF WAS ACCOMPLISHED. AT APPROX 5000' AFTER TKOF I SELECTED ENG ANTI-ICE ON SINCE THE TEMP WAS APPROX 3 DEGS C AND WE WERE ABOUT TO ENTER THE CLOUD BASES ON OUR CLB OUT OF PDX. APPROX 5 MIN LATER WE WERE LEVEL AT OUR INITIAL CLB ALT OF 9000' AND I OBSERVED THAT THE RIGHT ENG EPR WAS APPROX 15 LOWER THAN THE LEFT ENG. WHEN I ADVANCED THE RIGHT ENG TO MATCH EPR'S, I OBSERVED THAT THE THROTTLE WAS AHEAD OF THE LEFT ENG THROTTLE AND THAT THE RIGHT N1 N2 AND EGT WERE ALSO HIGHER THAN THE LEFT ENG. AT THAT TIME I SUSPECTED ENG ICING HAD OCCURRED AND MATCHED THE ENGS N1 AND N2 TACHS FOR PWR INFO. APPROX 5 MIN LATER, AND 10 MIN FROM SEA, I OBSERVED THAT BOTH EPR'S, N1 AND N2, TACHS HAD RETURNED TO A NORMAL MATCHED CONDITION AND THAT NO ENG DISCREPANCIES WERE NOTED. THE APCH WAS FLOWN WITH ENG ANTI-ICE ON WITH NO PROBS NOTED. ON LNDG AND TURNING OFF THE ENG ANTI-ICE, BOTH ENG EPR'S AND ALL PARAMETERS WERE NORMAL. NO LOG BOOK ENTRIES WERE MADE. I INFORMED THE OUTBND CREW OF THE DIFFERENCE IN EPR'S AND ADVISED THEM OF SUSPECTED ENG ICING AND THE NORMAL READINGS, PRIOR TO LNDG, AND TAXIING IN. THE NEXT MORNING WE WERE INFORMED THAT THE SAME ACFT HAD AN AIR RETURN SHORTLY AFTER TKOF FROM SEA.

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.