What was found
ATL - FLT 0504 - EN ROUTE DFW/ATL. SHORTLY AFTER LEVELLING OFF AT 37,000 FEET, A BURNING SMELL WAS NOTICED IN THE CABIN AND COCKPIT. PULLED RE-CIRCULATION FAN CIRCUIT BREAKERS AND SMELL SEEMED TO DISSIPATE. LANDED ATL WITHOUT INCIDENT. INSPECTED CABIN, COCKPIT, CARGO COMPARTMENTS. NO DEFECTS OR BURNING SMELLS NOTED. REPLACED RE-CIRCULATION FAN AND GROUND SENSE RELAY R2-59. SYSTEM GROUND CHECKED, NORMAL OPERATION. (X)