Nice to meet you, I was assigned to the maintenance section of the Kagoshima Plant from August. Originally, I was servicing the engine of a large aircraft at an airline, and I am new to the small aircraft industry, and every day I study every time I work.
I was wondering what to write this time, but I would like to talk about my experience with airlines.
Do you know how the plane is slowing down?
Large airplanes that you often see at airports weigh about 250 tons and land at speeds of about 300 km / h.
How do you slow down something like this to about 20km / h on the runway?
There are three main speed reducers to slow down an airplane.
First is the brake attached to the wheel. This slows down the tires themselves in the same way as you do with the car you are in.
Briefly, the brake disc is pressed with a pad to decelerate.
Have you ever been told by a car dealer when you inspected a car that “the pad is worn, so it’s time to replace it?”
The principle of wheel braking is the same for cars, small machines and large machines.
Due to restrictions on the speed and weight of the airplane and the distance of the runway, applying the brakes after landing will cause a considerable load and the brakes themselves will become hot. On large aircraft, touching the brake immediately after stopping will cause burns … Depending on how the brakes are used, even small aircraft may get burned.
The second deceleration method is the spoiler on the top of the wing. Also known as speed braking. This is decelerating the aircraft by creating air resistance (drag) with a plate protruding from the upper surface of the wing. One of the major purposes of the spoiler is to ensure that the tires touch the ground by reducing the lift of the wings and applying the weight of the aircraft to the tires.
Immediately after touchdown, lift remains on the wings, so not a little force is applied in the direction in which the airplane floats.
By canceling it with a spoiler, the wheel brakes can be applied more effectively.
If you sit next to the wings, you can see how this spoiler is operating up close. Please check it when you board the plane.
The third deceleration method is … You may have heard of thrust reversers and thrust reversers. This is decelerating the aircraft by directing about 80% of the thrust of the engine that has been moving the aircraft forward in the opposite direction.
There are various mechanisms, but mainly in large aircraft, the cowling (engine exterior) cracks from the middle of the engine, and reverse thrust is injected from there. If you look at the landing of the plane, you can see that the device is working.
By the way, it is difficult to understand, but turboprop machines also generate thrust by changing the angle of the propeller wings.
Medium and large aircraft mainly use normal brakes and two other ones, but small N-class aircraft have only normal wheel brakes due to the weight and landing speed of the aircraft itself.
As you can see, there is a difference between a large machine and a small machine even if one brake is taken.
I would like to deepen my knowledge and skills about small aircraft while making use of my experience at airlines.