As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD/ILM - FLT 6623 - DURING CRUISE AT 2,000 HOURS ON 4-2-98, AIRCRAFT MADE AN UNSCHEDULED LANDING AT IAD DUE TO LT OIL COOLER FLAP WOULD NOT CLOSE. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED OIL COOLER ACTUATOR. OPS CHECK OK. AIRCRAFT RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)