By Jack Kim SEOUL (Reuters) -Both engines of the Jeju Air plane that crashed last month contained duck remains, according to a preliminary report on Monday, with authorities still trying to determine what caused the deadliest air disaster on South Korean soil.

SEOUL, Jan. 27 (Korea Bizwire) — South Korean authorities investigating the tragic Jeju Air crash last month released a preliminary accident report Monday, revealing that the aircraft’s black box stopped recording approximately 2 kilometers before the plane approached the runway.

Seoul: The South Korean transport ministry on Saturday has revealed that the ill-fated Jeju Air flight, involved in last month’s deadly crash, received a warning from air traffic control about potential bird activity just one minute before its black box recording stopped.

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

The nation’s transport ministry reviewed structures near airport runways after the deadly crash of a Jeju Air flight late last month.

Pilots’ actions after the bird strike are an early focus of the investigation, according to people familiar with the probe.

South Korea will release by Monday a preliminary report on last month's Jeju Air plane crash that killed 179 people, the deadliest air disaster on the nation's soil, the transport ministry said on Saturday.

South Korea released a preliminary report into last month’s deadly Jeju Air Co. crash that offers more detail on the role of bird strikes in the disaster, while still leaving crucial questions unanswered.