South Korea’s authorities investigating last month’s Jeju Air plane crash have submitted a preliminary accident report to the UN aviation agency and to the authorities of the United States, France and Thailand,

The investigation into the deadliest air disaster on the country's soil remains ongoing, focusing on the role of bird strike and involving an analysis of the engines and the "localizer" landing guidance structure.

Investigators say they have found evidence of a bird strike on a passenger plane that crashed in South Korea in December and killed 179 people. The feathers and blood stains on both engines of the Jeju Air plane were from the Baikal teal,