What was found
CREW REPORTED DURING CLIMB ABOVE FL270, NR 1 ENGINE ROLLED BACK TWICE LOSING 10 PERCENT N1, WOULD NOT ACCELERATE AT CRUISE ALTITUDE. THRUST WAS IN DETENT AND AT FULL POWER, THRUST LEVERS WERE NOT LOOSE, CRUISE ALT FL 370. ALL ENGINE INDICATIONS REMAINED IN GREEN RANGE. NR 1 FADECS DID NOT ALTERNATE. AFTER LANDING NR 1 ENGINE SHORT DISP EICAS MESSAGE. RETURNED TO DEPARTURE AND DID NOT DECLARE AN EMERGENCY DUE TO THE ENGINE CONTINUED TO OPERATE NORMALLY. LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. PERFORMED CMC DOWNLOAD AND FOUND BIT 27 THAT RECORD E1 FADEC A FAIL. R & R THE FADEC A IAW AMM 73-22-01. THE OPS CHECK WAS GOOD. NO MESSAGE FOR SHORT DISP NOTED THE ACFT WAS RETURNED TO SERVICE.