179 people died in the Korean passenger plane accident! How deadly is the "bird strike"?

On December 29, local time, a passenger plane of Jeju Air in South Korea deviated from the runway and crashed into the airport wall while landing at Muan Airport in South Jeolla Province, South Korea. All 179 people on board, except for two flight attendants, were killed. This is the most serious air crash in South Korea in terms of casualties .

This is the accident rescue scene taken at Muan Airport in South Korea on December 29. Xinhua News Agency/Newsis News Agency

According to South Korean media reports, the crashed plane was a Boeing 737-800, 15 years old. The plane was trying to land on runway 1 at Muan Airport but found it could not land normally and had to make a go-around. The second attempt to land on another runway was due to the failure to lower the landing gear and the plane crashed on its belly. Video footage showed that the plane was unable to slow down after gliding to the end of the runway and collided with the airport fence before exploding and catching fire.

South Korean plane suspected to have hit a bird before crashing

South Korea's Ministry of Land, Infrastructure and Transport said at a press conference on the 29th that before the plane crashed at Muan Airport that day, the airport tower had issued a bird collision alert to the pilot of the plane. One minute later, the pilot sent a distress signal, and the plane crashed a few minutes after the distress signal was sent.

On the same day, South Korean media released a video that allegedly captured the moment a "bird hit a plane."

Screenshot released by South Korean media

Video footage showed that the plane still failed to slow down at the end of the runway, and was severely damaged and caught fire after colliding with the airport fence. People in the Korean aviation industry generally believe that it is more likely that the plane hit a flock of birds, causing the landing gear to malfunction.

More than 20,000 cases occur each year worldwide

Bird strike incident

Why can a small bird cause such great damage to an airplane? CCTV has previously done a popular science article on this: Birds are not very heavy and do not move very fast, but airplanes are just the opposite. According to the laws of physics, the impact force is proportional to the mass and the square of the speed. For example, a 100-gram sparrow collides with an airplane traveling at 400 kilometers per hour, which can instantly generate a two-ton impact force, which can damage the airplane at best and even cause the plane to crash and kill people. According to experts, the cockpit windows, sensors, and engine blades of an airplane are all more likely to be damaged by a bird collision.

Simulation experiment of bird strike on aircraft engine

GIF source: CCTV News

According to statistics from the International Civil Aviation Organization, there are more than 20,000 bird strikes every year around the world . The cost of bird strikes around the world is more than $10 billion each year. Bird strikes have become one of the most dangerous factors threatening aviation safety.

Recently, a "bird collision" incident also occurred in our country.

On December 20, Tibet Airlines flight TV9873 encountered a "bird strike" during takeoff. The crew immediately decided to return, and the plane landed safely with no one injured .

On December 5, at Xiamen Gaoqi Airport, a Xiamen blogger filmed this scene and posted a video with the following narration: I filmed a China Airlines flight being hit by a flock of flying birds when it landed at Gaoqi Airport. The flock of birds hit the nose of the plane, and then blood was clearly visible on the nose .

After landing and inspection by the airport maintenance staff, subsequent flights were carried out normally.

Bird strikes are difficult to avoid effectively due to the high-speed flight characteristics of aircraft. Aircraft take off at extremely high speeds, which may reach hundreds of kilometers per hour . Such speeds and climb rates often make it impossible for birds to avoid them in time .

Since the flying altitude of most birds overlaps with the altitude at which aircraft descend, land, take off and climb, more than 90% of "bird strike" incidents occur at airports or in the airspace near airports, mostly during the takeoff and landing of aircraft .

What to do if a bird hits a plane?

Wang Yanan, editor-in-chief of "Aviation Knowledge" of the Chinese Society of Aeronautics and Astronautics, said that when the situation is serious, such as when birds are sucked into an aircraft engine , the engine power will be instantly weakened or even lost . Modern commercial aircraft can usually complete at least 120 minutes of flight with another intact engine , which is enough for the aircraft to find a suitable alternate landing field.

However, if both engines are hit at the same time, most of the aircraft's power will be lost , and it can only rely on its limited gliding and control capabilities to move towards the emergency landing site.

In addition, the pilot's handling requirements are relatively stringent during the low-altitude and low-speed phase when about to land or just taking off.

Experts analyzed that in the Korean passenger plane accident, when the plane lowered its landing gear to prepare for landing, the speed and altitude of the plane should have been very low . The impact of the flock of birds at this time may have caused certain parts of the landing gear to malfunction. The plane could only touch the runway without the landing gear, and it was difficult for the pilot to control the direction of the plane.

Additionally, the aircraft's spoilers can be seen in the video, including the wings that were not fully deployed to slow the aircraft .

Whether it was some kind of malfunction caused by a bird strike or was related to the pilot's operation is something that needs to be clarified in subsequent investigations.

What can be done to prevent bird strikes?

For airports, daily bird repelling to prevent "bird strikes" is one of the most important tasks.

The "Management Measures for Bird Strike and Animal Intrusion Prevention at Transport Airports" issued by the Civil Aviation Administration of China requires that airport management agencies should establish or designate a department to be responsible for bird strike and animal intrusion prevention work , and should be equipped with sufficient personnel to engage in bird strike and animal intrusion prevention work based on factors such as the ecological environment, support model and airport operation volume.

Equip airport bird scarers

Driving a bird-scaring vehicle, carrying bird-scaring guns, gas cannons, voice-driven bird-scaring devices, bird-catching nets and other "weapons", they "fight wits and courage" with the flying birds. They will use various means such as sounds, lights, and smells that birds are afraid of to drive the birds away from the airport and ensure flight safety.

Biological bird repellent

Don’t think that only humans can become bird scarers. In many large airports in my country, a group of “indigenous people” have also successfully applied for the position of bird scarers.

In recent years, many domestic airports, including Beijing Daxing Airport, have been trying to train local falcons to drive away birds above the airport . The Harris hawk, which was first introduced to the airport, has been in service for many years and has made great contributions to bird-repelling work.

Improve the performance of the aircraft itself

In addition to biological bird repellents, modern aircraft have already taken into account the risk of collisions with foreign objects such as flying birds during the design and manufacturing stages, and will undergo rigorous bird strike tests . From the nose to the fuselage, from the wings to the landing gear, and then to the engine, every part that may collide with birds must undergo rigorous impact tests to meet the airworthiness requirements of bird strike resistance, thereby ensuring the safety of the aircraft.

Modern aircraft also use some bird strike prevention designs , which disperse the impact force through energy-absorbing structures and reduce the damaged area of ​​the fuselage structure. At the same time, the performance of single-engine landing is improved . Once an engine loses power due to sucking in a bird, it can land with the help of another engine. Even if the fuselage structure is damaged, it can return to the airport as soon as possible.

In addition, various places are also testing various new bird-repelling methods, including drones , to minimize the probability of "bird strikes" and make air traffic safer.

Comprehensive sources: Xinhua News Agency, CCTV News, Aviation Knowledge, National Emergency Broadcasting, etc.