What was found
TUL - DURING AIRCRAFT 'RCF' AFTER HEAVY C-CHECK, THE MAIN LANDING GEAR EMERGENCY EXTENSION SYSTEM WAS ACTUATED BUT DID NOT OPERATE PROPERLY. MAIN LANDING GEAR DID NOT EXTEND, COULD NOT RELEASE MECHANISM. CHECK AND RE-RIGGED EMERGENCY EXTEND CABLES. PERFORMED GEAR SWING WITH EMPHASIS ON EMERGENCY EXTEND SYSTEM. (M)