Geese swim in the water near Seosan, South Chungcheong Province, Oct. 28. Courtesy of Birds Korea

Bird strikes are a serious threat to aircraft at many of Korea's airports, and the problem is likely to worsen in the coming years with the introduction of more regional airports around the country, according to a nongovernmental organization (NGO) related to the study of birds.

Nial Moores, national director of Birds Korea, sent out the warning on Jan. 6, following the disastrous Jeju Air crash at Muan International Airport in South Jeolla Province, Dec. 29.

"There ... needs to be an honest reassessment of the suitability of the location of existing and of proposed airports — especially as it relates to the bird strike risk at each airport," Moores said in a blog post on birdskoreablog.org. "This is an urgent imperative because of the high number of new airports that are being proposed, almost all in bird-important areas near the coast."

A bird strike, possibly with a flock of birds, is currently believed to be one of the causes of the recent crash.

Moores mentioned that the runway there is currently being extended despite the airport's presence next to wetlands, which support around 40,000 waterbirds each winter.

"All along the west coast of the ROK and on islands like Baengnyeong, flocks of geese roost on or close to water. Near sunrise, they then fly out to feed in rice fields, sometimes flying 20 kilometers or more one way," Moores said.

"Based on this behavior, it seems highly probable that geese in Muan would try to use the reservoir immediately to the southeast of the runway for roosting. If there was disturbance at the reservoir they would likely congregate instead at low tide on the adjacent tidal flat. From there, the geese would then commute back and forth to rice fields to feed. This means that several hundred geese would likely commute back and forth across the runway on multiple dates between October and March. As this species has substantial mass, collision with a flock could be predicted to be very harmful to aircraft during takeoff or landing."

He pointed to the proposals for seven new airports to be built in coastal areas: Saemangeum in North Jeolla Province, Gadeok Island in Busan, Seosan in South Chungcheong Province, eastern Jeju Island, Baengnyeong Island in Incheon's territory, Hwaseong in Gyeonggi Province and Heuksan Island in South Jeolla Province. Many of these are located along important migratory routes and in important wetlands as well as other areas important to birds.

This map shows the locations of seven proposed airports, with a 13-kilometer radius marked by a red circle around each. Muan International Airport has been in operation since 2007. The Ulleung Island airport is under construction. Several others have budgets allocated to them or received some kind of initial approval. Courtesy of Birds Korea

He also cited concerns over another airport currently under construction on Ulleung Island, an island with a population of around 10,000, which Moores said is projected to cost $560.9 million.

"Data available to government clearly indicates that at least seven and perhaps all eight of these new airports, once operational, will inevitably experience a high or an exceptionally high risk of bird strike to aircraft," he concluded.

The British national called for reassessing all of these airport proposals and operations, stating that all such reassessments of airport locality and operation in Korea need to be framed clearly by the guidance provided by the International Civil Aviation Organization (ICAO), a U.N. agency charged with ensuring aviation safety around the world. He also added that there are economic and other environmental reasons beyond protecting birds for reconsidering the need for these extra airports.

A small flock of Taiga bean geese (with a single globally endangered swan goose) swim in a lake near a reclamation site, with several globally endangered Oriental storks feeding along the edge of the lake behind them, November 2024, in front of the most recent proposed site for the airport on Baengnyeong Island. Courtesy of Birds Korea

Moores explained that not all species of birds pose the same level of risk to airplanes, citing the ICAO, which identifies factors in the severity of a bird strike based on "the size of the animal and its tendency to flock or congregate."

"A plane colliding with a single small bird is unlikely to pose much risk to the aircraft," Moores added. "Aircraft colliding with large flocks of birds, which have a high mass (body weight) pose a much higher risk. Larger-bodied birds which often form large flocks, like geese and cormorants, pose the highest bird strike risk if they frequently fly across the runway or heavily used flight paths."

He highlighted three main steps that decision-makers can take to reduce the risk of bird strikes.

"The first, and wisest step, is precautionary," he said. "That means avoiding building airports in areas known or found to have large concentrations of large-bodied birds — essentially migratory bottlenecks and wetlands ... If safety of aircraft is the priority, then many of the currently proposed airports should have been canceled during the initial project scoping period. There is still time to take this step."

The second step comes if an airport is deemed truly essential and the risk of bird strike is considered acceptable. "This is the stage where a series of difficult and sometimes expensive decisions on mitigation need to be taken — including reorientating proposed runways to avoid the most hazardous areas and ... enacting ecological measures to reduce the attractiveness of the airport area to birds before operation."

The third step, he said, is to reduce bird strike risk as much as possible through scaring off birds, "especially near runways, but if needed also all the way out to 13 km from the airport," Moores said. This figure is based on the numbers that show 95 percent of documented bird strikes take place below 610 meters above the ground, and an aircraft on a normal approach would descend into this zone approximately 13 km from the runway, according to the ICAO.

Geese fly over Maehyangni Tidal Flat at low tide in Hwaseong, Gyeonggi Province, Oct. 13, 2020. Plans for a new airport in the vicinity have received initial approval. Courtesy of Birds Korea

Moores, who has a doctorate in the conservation of avian biodiversity, has field experience at all nine mentioned sites. This ranges from two to three visits at some sites, to more than 200 days of fieldwork at both Saemangeum and Baengnyeong Island. He has independently reviewed four environmental impact assessments for airports (Jeju, Saemangeum, Busan and Muan). In 2024, he gave expert testimony in an ongoing legal challenge to the airport project at Saemangeum, expressing grave concerns about the bird strike risk and impacts on biodiversity to highlight flaws in its environmental impact study.

"We do not yet know what the investigation into the Muan air crash will find," he said. "Two things do seem certain, however. The first is the prolonged suffering of all those impacted by the Muan air crash — our sincerest condolences to them. The second is that if safety really is the priority, then a review of airport safety needs to consider not only aircraft maintenance and permanent hazards. It also needs to include a comprehensive and transparent reassessment of the bird strike risk."