As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD - FLT 6623 - DURING CRUISE AT 1815 HOURS ON 11-27-98, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO RT ENGINE OIL CONTAMINATION WARNING LIGHT ILLUMINATED. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED RT ENGINE. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)