As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SUPPLEMENT INFORMATION: CORRECTED PART NUMBER IAD FLT 5850 THE CREW REPORTED SMOKE IN THE COCKPIT ON CLIMBOUT. THE AIRCRAFT RETURNED TO IAD AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED AND REPLACED THE NR 1 NOISE ATTENUATOR DUCT. OPERATIONAL CHECKS WERE GOOD.