The Unsolved "Landing Gear" Mystery. Why It Didn't Work.

[Anchor]
Jeju Air's accident The plane's wheels, or landing gear, were not working and the plane landed on its fuselage.

Why didn't the landing gear work?Investigation is being conducted with all possibilities open, from faulty

equipment to engine failure to power shutdown.

I'm reporter Lee Hyungwon.

[Reporter]
The landing gear is responsible for controlling speed and absorbing shocks when the plane lands.

The plane did not operate this landing gear during the second landing, but for now, it is a possibility of a defect in the device itself.

However, as the speed was normally lowered ahead of the first landing, it is highly likely that a simple defect in the airframe caused the landing gear problem.

[Jeong Yoon-sik / Professor of Air Operations at Catholic Kwandong University: (The landing gear was lowered and raised in the first landing attempt). It reduces the plane's speed to 145 knots. You have to get down to the frame to land to reduce it to that speed. (If there's a landing gear problem) I just go back down. But posting it means that the system was normal until then.]

The possibility of a power cut-off was also raised due to poor communication between the control tower and the accident airliner.

However, the fact that the radio was radioed, such as obtaining permission to land just before the accident, can be grounds that it is not an electrical system problem, so further investigation is needed.

[Joo Jong-wan / Director of Aviation Policy at the Ministry of Land, Infrastructure and Transport] (Whether or not the power shutdown is) We can only find out by checking the entire communication by looking at communication records or something. What was the situation (you need to know) whether there was communication by time zone or not....]

The most convincing hypothesis to date is a failure of both engines.

If the right engine fails after hitting a flock of birds,
This is because it is estimated that the landing gear could have been lowered by supplying hydraulic pressure to the power transmission unit connected to the left engine
.

If both engines are broken, you have to manually lower the landing gear, but the problem is time.

It takes at least 1 minute and 30 seconds to give up and decide to land the fuselage.

[Kim In-kyu / KAI Flight Training Center: If both engines stop and there is not enough hydraulic pressure, it operates slowly in other ways, but it slows down significantly. If you return in a hurry (like this accident), there probably wasn't enough time for that....]


with the cause of landing gear in limbo
The Ministry of Land, Infrastructure and Transport is investigating the black box analysis and the contents of the control tower and the accident communication.

I'm Lee Hyungwon of YTN.

Edit
video: Lee Eunkyung

Design:Jeong-ok