What was found
ACFT FLEW 3 LEGS, NO PROBLEMS. ON 4TH TAKEOFF, AT 100 KNOTS, RUDDERS LOCKED. T/O ABORTED. DURING TAXI BACK, RUDDER & NOSE STEERING WORKING NORMALLY. RUDDER BIAS TESTED NORMAL. CNTRL LOCK RELEASED. T/O ATTEMPED & AT 100-105 KNOTS, RUDDER CNTRLS LOCKED AGAIN. T/O ABORTED & ACFT RETND. VISUAL INSP MADE, NO PROBLEM FND. A 3RD T/O WITH RUDDER BIAS OFF WAS ORDINARY WITH EVERYTHING WORKING NORMALLY. ACFT FLOWN HOME WITH NO FURTHER PROBLEMS. RUDDER BIAS ACT DISASSEMBLED AND INSP. APPROX 1 TEASPOON OF WATER REMOVED. ACT INSP IAW CESCARD NR A272202 & B272202. RUDDER BIAS SYS INSP IAW CESCARD NR 272002. RUDDER BIAS THERMOSTAT TESTED OK. LINES TO RUDDER BIAS ACT PURGED. ACT REINSTALLED, T/O & LDNG OK.