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.

The feathers and blood stains on both engines of the Jeju Air plane were from the Baikal teal, a type of migratory duck that files in large flocks, according to a preliminary investigation report published on Monday.

South Korean authorities concluded search and recovery operations and an investigation into the Dec. 29 crash of a Jeju Air plane that killed 179 people. The Korea JoongAng Daily said Sunday that the families of the victims agreed to end the investigation after authorities disclosed details about bird strikes linked to the crash.

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

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.

South Korea plans to enhance its regulation of domestic low-cost carriers and impose strict penalties on those that do not comply with new safety standards, Yonhap News Agency reported. On Park Sang-woo,

SEOUL: Both engines of the Jeju Air plane that crashed last month contained duck remains, according to a preliminary report on Monday (Jan 27), with authorities still trying to determine what caused the deadliest air disaster on South Korean soil.

South Korea will extend runway safety areas and redesign infrastructure after the crash of a Jeju Air Co. flight last month that killed almost everyone on board, sparking criticism that the design of the airport might have exacerbated the accident.