Jeju Air: Bird feathers were found in the engines of the crashed South Korean plane

Authorities previously said they had flight data and cockpit voice recorders from the plane stopped writing about four minutes before the disaster.

Experts who flew the same type of aircraft involved in the crash have also questioned the presence of concrete barriers along the runway – some believe the death toll would have been lower had they not been there.

The concrete structure houses a navigation system that helps aircraft land, known as a localizer.

South Korea’s Ministry of Transport said the system could be found at other airports in the country and even abroad.

Last week, officials announced they would change the specific obstacles used for navigation at seven airports in the country. All seven airports will be adapted to runway safety zones after the review.

A preliminary report was submitted to the United Nations aviation agency and authorities in the United States, France and Thailand.