What happened
Shortly after liftoff, a passenger seated in row 18 reported observing flames emanating from the overhead area on the right side of the aircraft. In response to the report, a flight attendant used a Halon fire extinguisher to suppress the area and subsequently notified the flight deck of the incident. While the passenger reported seeing flames, the flight attendant did not personally observe any flames during the suppression process.
The crew performed an emergency landing at the departure airport, and the aircraft arrived without further incident. There were no reported injuries among the passengers or crew.
The investigation
Investigators examined the overhead area near row 18 and determined that a cannon plug connector located adjacent to the light assembly had shorted. Further inspection of the connector revealed that pins in the mating halves of the connector were damaged. The damage appeared to have been caused by an attempt to make a previous connection.
Efforts to replicate this specific connector failure mode through research were unsuccessful. A review of the operator's maintenance records did not indicate whether any recent maintenance had been performed on the connector. Additionally, the operator was unable to verify that the connector or the surrounding area had remained unserviced during a previous stopover.