As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - FLT 86 - EN ROUTE ORD/LHR, DURING CRUISE, SMOKE NOTED IN CABIN. ACCOMPLISHED ABNORMAL PROCEDURES AND SMOKE SUBSIDED. AIRCRAFT PROCEEDED TO LHR AND LANDED WITHOUT INCIDENT. PLACARDED NR 1 CABIN RECIRCULATION FAN INOPERATIVE. SUBSEQUENTLY REPLACED NR 1 CABIN RECIRCULATION FAN AT ORD. SYSTEM GROUND CHECKED NORMAL OPERATION WITH NO SMOKE NOTED. (M)