What was found
PILOTS REPORTED AFTER PERFORMING A SIMULATED WING FIRE MANUVER (A STEEP TURN TO THE LEFT) THEY HEARD A LOUD BANG AND THEN LOST CONTROL OF THE RUDDER. THE AIRCRAFT LANDED SAFELY. MAINTENANCE INSPECTED THE RUDDER SYSTEM AND FOUND THE WELD ASSEMBLY GEARS HAD (JUMPED) A TOOTH AND REDUCED RUDDER TRAVEL TO APPROX .3333 OF NORMAL TRAVEL. AFTER REMOVAL OF THE WELD ASSEMBLIES MAINTENANCE FOUND THE BULKHEADS THAT THE OUTBOARD RUDDER BEARINGS MOUNTED TO HAD ELONGATED HOLES THAT WOULD ALLOW THE BEARING TO SHIFT FORWARD WHEN EXCESSIVE PRESSURE WAS APPLIED TO THE OB RUDDER PEDALS ON EITHER SIDE OF THE COCKPIT. THE RUDDER BEARINGS SHOWED NO ABNORMAL WEAR FOR THIS TYPE OF AIRCRAFT. ONE TIME OCCURANCE BEFORE SB 98-3.