What was found
DURING EXTENSION OF THE LANDING GEAR FOR LANDING, THERE WAS NO LEFT DOWN AND LOCKED INDICATION. MANUAL HYDRAULIC EXTENSION WAS INEFFECTIVE. PNEUMATIC EXTENSION SYSTEM WAS ACTIVATED WHICH LED TO A DOWN AND LOCKED INDICATION AND AN UNEVENTFUL LANDING WAS MADE. DURING INSPECTION OF THE LEFT MAIN LANDING GEAR, THE MAIN LANDING GEAR EXTENSION ACTUATOR BOLT WAS FOUND MISSING. A DETAILED INSPECTION FOUND THE BOLT HAD APPEARED TO HAVE SHEARED. SUBMITTER RECOMMENDED THIS BOLT BE INSPECTED AND/OR REPLACED DURING INSPECTIONS.