As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - FLT 46 - EN ROUTE ORD-LHR, DURING FLIGHT EMERGENCY EXIT LIGHTS ILLUMINATED FOR 2 MINUTES THEN EXTINGUISHED. LANDED LHR WITHOUT INCIDENT. CYCLED EMERGENCY EXIT LIGHT SWITCH OFF THEN ARMED AND ACCOMPLISHED EMERGENCY EXIT LIGHT TEST, ALL LIGHTS FUNCTION AS NORMAL. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)