What was found
NUMBER ONE ENGINE SURGED DURING CLIMB, N1 WENT FROM A TARGET OF 92 PERCENT TO 94.3 PERCENT. ALSO, HAD A 1,000 POUND INCREASE IN FUEL FLOW, THROTTLE WAS RETARDED AND ENGINE SURGED TWO MORE TIMES BEFORE IT STABILIZED. ENGINE SURGING WAS CAUSED BY AN INTERMITTENT FAILURE OF THE MAIN ENGINE CONTROL ROTARY VARIABLE DIFFERENTIAL TRANSDUCER. THE MAIN ENGINE CONTROL WAS REPLACED AND CHECKS OK.