What was found
AT 1150Z FL390, SMOKE WAS DETECTED IN THE COCKPIT. APPEARED TO BE LOW IN COCKPIT. DEFERRED RIGHT PACK PER MEL 21-51-1. FOUND RIGHT PACK SEIZED UP. REMOVED AND REPLACED RT ACM IAW M/M 21-51-03-4, RT PACK OPS CHECKS NORMAL. THIS CLEARS M 282798.