South Korean authorities said on Wednesday they will change the concrete barriers used for navigation at some airports across the country after the Jeju Air crash that left 179 people dead.

The South Korean government have said it will remove the concrete localizer structure that a Jeju Air Boeing 737-800 crashed into at Muan International Airport.

Investigators have confirmed the presence of bird feathers and blood in both engines of the Jeju Air jet that crashed last month in South Korea, killing 179 people, according to a source familiar with the ongoing probe.

The two flight recorders on board a South Korean airliner stopped working before the jet crashed during an emergency landing and subsequent crash that killed 179 of the 181 people on board, officials said Saturday.

The airport is the site of the Dec. 29 crash of the Jeju Air Boeing 737-800 jet that killed 179 passengers on board.

The two black boxes on the Boeing jet involved in the worst aviation disaster on South Korean soil stopped recording about four minutes before the accident, the transport ministry said on Saturday. South Korean investigators previously said the flight data and cockpit voice recorders were key to finding out the cause of last month's crash that killed 179 people.

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.