What was found
PILOT TAXIED FOR TAKEOFF AND USED THE RUDDER SYSTEM TO MAINTAIN DIRECTIONAL CONTROL BOTH ON THE GROUND AND DURING THE TAKEOFF ROLL. WHEN IN THE AIR HE NOTICED A LACK OF YAW CONTROL DURING A CLIMBING TURN, THE FLIGHT WAS ABORTED AND A NORMAL LANDING ACCOMPLISHED. UPON INSPECTION WE FOUND THE RIVETS ATTACHING THE LOWER RUDDER TUBE PN 420144-1 TO THE TUBE FITTING PN 420015-501 WERE SHEARED, WHICH CAUSED THE RUDDER SYSTEM TO BE INOP. THE NIGHT BEFORE THIS FLIGHT A HIGH WIND CONDITION OCCURRED WITH STRONG ENOUGH WINDS TO CAUSE THE RUDDER LOCK TO SLIP OFF AND ALLOW THE RUDDER TO BE PUSHED AROUND. A VISUAL INSPECTION WAS CONDUCTED THE MORNING OF THE FLIGHT WITH NO DISCREPANCIES NOTED AND ALL RIVET HEADS ON THE TUBE FITTINGS WERE PRESENT, HIDING THE SHEARED RIVETS UNDERNEATH.