How Do Airplanes Stop?
How do airplanes stop? Stopping of an airplane takes place when a combination of a few things work together to slow down then stop the airplane. Most commercial planes have three systems to stop the airplane. The first one is the sequence of flaps. Look at the image at right and notice how flaps are extended on descending. This helps the aircraft to decelerate, thus reducing the speed before touchdown. Pilots can extend the flaps to any configuration to meet the demand of deceleration. The lower percentage of the flaps helps to give the plane a lift but as a certain percentage is crossed (normally 30%), the drag starts to prevail over lift, causing the airplane to slow.
Spoilers, also called air brakes and speed brakes is another system to slow down an airplane before touchdown and just after landing. Spoilers apply a backward force on the wings with the help of air to slow the airplane. If you have ever looked out at a wing just before landing, you have probably seen them but only certain spoilers are opened in the air while others are locked out. See how spoilers are pointing up on the wings, in the right image.
The second system of slowing down an airplane is called reverse thrusters, which comes in action right after the airplane wheels touch the ground. The purpose of reverse thrusters is to redirect engine thrust to help stop the airplane. See in the image at right how the frame that surrounds the engine looks if it’s fallen apart. This forces the air that’s coming out of the engine to be pushed up and down, altering the engine thrust. This in turn slows the airplane significantly.
You can see when the reverse thrusters are in action. They normally operate until the airplane is slowed down to a manageable speed. The noise at that time is intense for a few seconds. You can also see the water or dust droplets kicking out of the engine. The power of the engines is clearly heard and seen. This is an amazing experience. Because airplanes are getting bigger and heavier and just need more advanced braking technology, all of the newer airplanes have them.
The third system in the process of slowing and stopping an airplane is wheel brakes. The wheel brakes are applied gradually once both the front and rear wheels have touched the runway. Commercial airplanes have, at the minimum, wheel brakes for stopping. If the wheel brakes were just used to stop the airplane, it would take a very long runway length and the stopping interval would be greater. Some airplanes have auto brakes and the pilot can set their intensity to low, medium or high. Auto brakes are also used on takeoff and will apply braking automatically in the event the take off is aborted over a certain speed.
All three of these systems are important in slowing and stopping an airplane.