Not a RTLU expert, but I can try explain scenario for this problem based on available information. Rudder position does not play role and gust lock function is not available in system. Damaged mechanical stops are internal stops of actuating screws (rotating shafts) inside mechanical part of RTLU, not rudder travel (variable) stops. Damage on this stops is generated by repetetive activation of "emergency return to low speed" mode, which drive a rotating shaft inside TLU until reaching mechanical stops. During normal RTLU operation shaft stops rotating before reaching mechanical stops, because system uses closed loop feedback from position transducer. This normal function does not put any load to mechanical stops. Emergency return to low speed condition will be activated on ground if CB for FAC are closed (it means RTLU is electrically supplied) and both FAC P/B are OFF and slat extended or ADIRU OFF (ADR data invalid for FAC) and slats extended. Yes, on ground is RTLU in low speed position, but can be moved further to hit mechanical stops. This is my explanation, at least in basis...
Last edited by LEVEL600; 26th May 2015 at 13:06.