A B737-300 IN CLB DECLARED AN EMER AND DIVERTED DUE TO ACFT REQUIRED 80 PERCENT OF L AILERON CTL YOKE TO MAINTAIN LEVEL FLT.

Narrative

AFTER DEP FROM ZZZ; APPROX 3500 FT MSL; HIT WAKE TURB FROM A DEPARTING B767-300 HEAVY. EXPERIENCED MODERATE TURB. AFTER WE WERE OUT OF THE TURB; IT TOOK APPROX 80 PERCENT OF LEFT CTL WHEEL DEFLECTION TO MAINTAIN WINDS LEVEL. CONTINUED CLB TO SMOOTH AIR. UNABLE TO DETERMINE WHAT WAS WRONG. ADVISED ATC WE HAD A FLT CTL PROB; DECLARED AN EMER; RETURNED TO ZZZ FOR A NORMAL APCH AND LNDG. AFTER GATE ARR; FOUND R AILERON UP ABOUT 6-7 INCHES (RIGHT WING DOWN). MAINT FOUND FOLLOW-UP CABLE BROKEN IN R MAIN WHEEL WELL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE AILERON PROB WAS COUNTERED BY THE LARGE DEFLECTION OF THE CTL YOKE AND ONLY 5 UNITS OF RUDDER TRIM AS IT WAS FIRST THOUGHT IT WAS A RUDDER PROB. THE RPTR SAID THE FO MADE A VISUAL CHK OF THE R AILERON AND IT WAS STUCK UP FULL DEFLECTION. THE RPTR STATED ON THE GND; MAINT FOUND AN AILERON CABLE BROKEN IN THE R WING 48 INCHES OUTBOARD OF THE SPOILER MIXER TWR SHAFT IN THE MAIN WHEEL WELL. THE RPTR SAID HE STILL QUESTIONS WHY THE AILERON WAS DEFLECTED TO FULL UP AND REMAINED IN THIS POSITION ON THE GND. THE RPTR STATED THE AIRPLANE STILL HAD PLENTY OF CTL AND ONLY USED 5 UNITS OF RUDDER TRIM AS IT WAS FIRST SUSPECTED A RUDDER PROB.