At Jeonnam Muan International Airport, a large number of casualties occurred when a Jeju Air aircraft landed without its landing gear (the wheels used during landing) functioning. Various speculations have arisen regarding the cause of the accident. It is possible that the landing gear failed to operate after the aircraft collided with a flock of birds in the air, but there are also analyses suggesting that pilot error is suspect.
A representative from an airline, identified as Mr. A, who is a former pilot for Jeju Air, noted in a phone call with CHOSUNBIZ on the 29th that "the failure of the landing gear to descend could be a result of pilot error" and added, "Even if the aircraft collides with a flock of birds and the engine fails, there are ways to lower the landing gear."
On that day, the passenger aircraft approaching runway 1 at Muan International Airport attempted a first landing but was unable to land normally and went around before trying to land again. The aircraft attempting to land could not reduce its speed until it reached the end of the runway, colliding with a structure at the end of the airport, resulting in damage to the fuselage and causing a fire.
The aircraft appears to have attempted a belly landing because the landing gear did not deploy normally. While it is possible that the engine failed after colliding with a flock of birds, there are also analyses indicating that the engine failure and the landing gear malfunction are unrelated.
Mr. A explained that "the landing gear is a system that descends when a lever is pulled in the cockpit, activating the hydraulic system," adding that "even if the hydraulic system fails, there is a system in place to lower the landing gear using gravity." He continued, "The Boeing 737-800 involved in the accident has no separate door to block the landing gear, making it easy to lower through gravity."
He stated that "if the landing gear fails, the aircraft will first inform the control tower about the situation, and the control tower will contact the fire department. Then, fire trucks will spray foam on the runway to prevent the aircraft from catching fire during an emergency landing." He added, "Attempting to land before the foam measures were implemented can also be seen as an error."
If the aircraft that had the accident collided with a flock of birds, it is also possible that the mechanism for lowering the landing gear was damaged in the process. Jeong Yoon-sik, a professor in the Department of Aviation Operations at Catholic Kwandong University, said, "Even if the hydraulic system fails, there should be auxiliary equipment, but activating it takes time," noting that "it took less than 3 to 4 minutes for the accident to occur, while activating the auxiliary device can take up to 15 minutes."
It is also possible that there were issues with the braking system. Choi Ki-young, a professor in the Department of Aerospace Engineering at Inha University, pointed out that "if a belly landing is performed, the aircraft must increase drag using the wings to slow down, but this isn’t visible in the video," and mentioned that "it seems problems arose with both engines of the aircraft, and if the engines are not functioning, commands from the pilot may not be transmitted."