What was found
SMOKE & FUMES IN THE COCKPIT AND CABIN, IN FLIGHT. IAW FIM TASK 21-20-00-810-801-A, FOUND THE RECIRCULATION FAN INOPERATIVE. REMOVED AND REPLACED THE RECIRCULATION FAN IAW AMM 21-24-01. OPS CHECKED GOOD. NO DEFECTS NOTED. PERFORMED ETN-EM-72-034, OPS CHECKED GOOD, NO DEFECTS NOTED. ON FURTHER INVESTIGATION, FOUND THAT WHEN OPERATING THE NR 2 PACK OFF, APU BLEED SMOKE AND BURNING ODOR ENTERED THE CABIN. REMOVED AND REPLACED THE RT ACM IAW AMM 21-51-03.