What happened
While operating at cruise altitude, the captain and first officer observed smoke emanating from beneath the instrument panel glareshield. In response to the smoke, the flight crew donned oxygen masks and smoke goggles before executing the required emergency checklists.
The crew proceeded to shut down the aircraft generators, which resulted in the smoke clearing from the cockpit within approximately four minutes. The aircraft subsequently landed, and all passengers deplaned without incident. There were no injuries reported.
The investigation
Post-flight examination of the instrument panel area identified burnt wiring and a charred position light switch. A detailed inspection further revealed that the autotransformer for the oscillating position light located on the left wingtip had shorted out. Additionally, investigators found that the circuit breaker for the position light was stuck in the closed position.