What was found
DURING CLIMB-OUT, AT APPROXIMATELY 20,000 FEET THE CREW RECEIVED A SMOKE CARGO MESSAGE. AFTER TURNING OFF THE CARGO FAN WHLE COMPLYING WITH THE IMMEDIATE ACTION ITEMS, THE SMOKE CARGO MESSAGE, CARGO FIRE X NORMAL AND STAND BY RED LIGHTS ALL EXTINGUISHED. NO FURTHER MESSAGES WERE NOTED. THE AIRCRAFT LANDED SAFELY. MAINTENANCE WAS UNABLE TO DUPLICATE THE DISCREPANCY. AS PRECAUTIONARY MEASURE, MAINTENANCE REMOVED AND REPLACED BOTH CARGO SMOKE DETECTORS. OPS CEHCKS GOOD. AIRCRAFT OK FOR SERVICE. (M)