What was found
AFTER T/O, A/F VIB DEVELOPED AT 250 KTS/5000 FT STRAIGHT AND LEVEL. SLOWED TO 220 KTS VIB STOPPED, CLIMBED TO 23,000 FT A/S 250 VIB AGAIN AND SLOWING THROUGH 235 KTS VIB STOPPED. NO VIB BELOW 235 KTS, NO VIB THROUGH YOKE OR RUDDER PEDALS. ECAM STS NOT CAT 3/INCRS LDG DIST BY 1.1. FOUND FRONT NR 1 FAN CASE ASSY WORN, REMOVED AND REPLACED PER MM 72-23-01. RAN NR 1 ENG AND NO VIB, OK FOR SERVICE AND LEAK CHECK GOOD. REMOVED AND REPLACED FLEX LINE FOR HYD, PRESS CHECK GOOD. PERFORMED A/FLT SYS AND A/SELF TEST, NO FAULTS.