"Bird strike" is identified as the cause of the aviation disaster that occurred in Muan, South Jeolla Province. Bird strikes are one of the serious safety issues that can occur during aircraft operations, causing around $1.2 billion (approximately 1.77 trillion won) in damages to the global aviation industry annually.
According to the scientific community on the 30th, bird strikes cause damage to nearly half of the aircraft engines, and it has been revealed that even a small bird can create shock equivalent to over 300,000 times its weight. Consequently, there are suggestions for changing engine materials to withstand bird strikes and for training on bird avoidance and safe landing maneuvers in preparation for accidents.
According to a report by the European Union Aviation Safety Agency (EASA) and researchers at the Czech Technical University in Brno, 44% of all bird strike incidents to date have occurred in aircraft engines. Following that, 31% occurred in wings, and 13% in windows, indicating that accidents are primarily concentrated at the front part of the aircraft. Most aircraft worldwide, including the passenger planes of Boeing, use 'turbofan engines.' This type of engine, in particular, has a high probability of encountering bird strikes.
Turbofan engines operate by rotating fan blades to draw in and compress air, then burning it along with fuel to generate thrust. Professor Yoon Goon-jin from Seoul National University’s Department of Aerospace Engineering notes that "civilian aircraft, such as Boeing and Airbus models, are equipped with a type of turbofan called 'high-bypass turbofan,' which increases the probability of birds being sucked in due to the physically larger size of the fan."
Bird strikes typically occur at low altitudes below 2,500 feet (approximately 762 meters), frequently during takeoff, initial ascent, or landing approach phases. A single small bird can exert shock on an aircraft engine equivalent to several tens of tons. This highlights the significant focus on the specific damage patterns and preventive measures for bird strikes among scientists.
Even a small bird colliding with an engine can produce an instantaneous shock of several tens of tons. According to a report presented by the Graz University of Technology in Austria, when a 75-gram starling collides with a jet engine at a speed of 470 km/h, it generates an instantaneous shock of 2.5 tons, representing an impact over 330,000 times its weight. When colliding at the same speed, a 1.8 to 2.3 kg cormorant exerts 20 tons of shock, while a Canada goose weighing up to 4 kg delivers 38 tons of shock.
Professor Kim Dong-hyun from the National University of Gyeongsang noted that "in Korea, bird strikes typically involve species such as the plover, cormorant, and pigeon," and added, "the size of the bird and its speed at the time of impact can vary the effects on the engine." The weight of a plover ranges between 17 to 55 grams, while a pigeon (rock pigeon) weighs around 230 grams.
When the shock from a bird strike damages the fan blades inside the turbofan engine, it can have repercussions on the fuel system line as well. Professor Yoon stated, "If a large bird enters the engine and collides with the rapidly rotating fan blades, it first results in the breakage and loss of those blades."
Professor Yoon further explained, "If damage occurs to the blades, it can lead to severe vibrations and reduced engine power, decreasing flight safety. If birds or blade debris get sucked into the engine and damage the fuel system line, a fire may occur, potentially leading to an accident in the worst-case scenario."
Researchers at Xiamen University in China analyzed the effects of individual birds on blades during collisions with bird flocks in May of this year, modeling the probabilities of collisions and the potential for blade damage. They found that while an impact at the blade tip disperses shock energy due to the blades' high rotational speed, multiple impacts occurring near the blade root can result in severe damage.
Professor Yoon stated that "not only do bird strikes on the engine present a challenge, but impacts on the wings can also affect the operation of high-lift devices necessary for landing, thereby influencing safety." However, it is difficult to completely prevent collisions between aircraft and birds. Professor Yoon suggested that "using titanium or composite materials with good impact resistance for the engine and blade components, along with employing bird detection radar for evasive operations, could enhance stability, as well as training on safety landing procedures in the event of unavoidable collisions."
Reference materials
Aerospace (2024), DOI: https://doi.org/10.3390/aerospace11060434
Transportation Research Procedia (2021), DOI: https://doi.org/10.1016/j.trpro.2021.11.120