What was found
(CAN) ON FINAL APPROACH, WITH FLAPS SET TO 17 DEG, THE CREW NOTICED THAT THEY WERE HAVING TO APPLY A SUBSTANTIAL AILERON CORRECTION. WHEN THE FLAPS WERE SELECTED FULL DOWN FOR LANDING, NO MOVEMENT WAS NOTED. THE CREW SUSPECTED A SPLIT FLAP CONDITION AND LANDED AS CONFIGURED, INCREASING VREF BY 15 KNOTS. UPON INSPECTION, THE RT OTBD FLAP WAS FOUND TO BE FULLY RETRACTED, AND NON-FUNCTIONAL DUE TO A BROKEN DRIVE CABLE. IMPROPER RIGGING OF THE FLAP PROTECTION SYS IS SUSPECTED TO HAVE ALLOWED THE EXCESSIVE, 17 DEG, TRAVEL PRIOR TO DISABLING THE SYS.