Incident Overview
Approximately one hour after departure, while cruising at an altitude of 34,000 feet above mean sea level, the flight crew of a transport category airplane detected an electrical burning odor. Subsequently, the flight engineer observed smoke emanating from the center console in the cockpit. The flight continued without further incident and resulted in an uneventful landing.
Post-Flight Examination
After landing, mechanics and Federal Aviation Administration (FAA) inspectors conducted an inspection of the aircraft. Their examination identified a hot lower incandescent lamp dimmer as a source of the odor and smoke. Approximately two hours after electrical power had been removed from the component, the dimmer reportedly burned a mechanic who came into contact with it.
Component Analysis
The dimmer and its associated circuit breakers were removed from the aircraft for further examination. Investigators noted scorching around the dimmer LV1 lead and on the lower side of both circuit breaker covers. The switch and related circuit breakers were subsequently sent to the National Transportation Safety Board (NTSB) Materials Laboratory for detailed analysis. However, these components were lost in transit and never reached the laboratory, preventing further examination.
Findings
No additional components or systems were reported as damaged. The specific aircraft type, registration, operator, and other identifying details are not disclosed in the available information. No injuries or fatalities beyond the reported mechanic burn were documented in the source.