What was found
AFTER TAKE OFF FROM DFW CREW REPORTED SMOKE IN COCKPIT. FLIGHT AIR RETURNED BACK TO DFW. LANDING WAS UNEVENTFUL. MAINTENANCE COMPLIED WITH FIM 21-20-00-810-801-A AND DETERMINED SMOKE IN COCKPIT WAS DUE TO PACK NR 1 FAILURE. AIRCRAFT RELEASED IAW MEL 21-51-00-3, CATEGORY "C". AIRCRAFT RETURNED TO SERVICE. THE AIRCRAFT LANDED, MAINTENANCE REMOVED AND REPLACED THE NUMBER ONE RECIRCULATION FAN, OPERATIONALLY TESTED WITH NO DEFECTS, REMOVED THE MEL, AND THE AIRCRAFT WAS APPROVED OFR RETURN TO SERVICE.