Some are placed in the front, some are placed in the back, so where should the propeller of an airplane be placed?

Since the advent of airplanes, propeller planes have always occupied an important position. Before the end of World War II, almost all airplanes were propeller planes. Even in today's world, propeller planes' excellent low-speed and take-off and landing performance are still unmatched by other aircraft.

As the name implies, a propeller plane is an aircraft that converts the engine power into thrust through a propeller. The appearance of modern propeller planes is also varied. Some propellers are placed in the front, and some are placed in the back. What is the secret? Where should the propeller of an aircraft be placed? In fact, propellers are really a big problem for propeller planes, because whether they are placed in the front or in the back, it seems that it is not the best choice. Most propeller planes we have seen have their propellers placed in the front, but this does not mean that placing them in the front is the best choice.

Why put the propeller at the front of the plane?

A propeller plane is an aircraft that converts the power of the engine into power through a propeller, so the propeller is never an isolated individual, it always stays with the engine, so putting the propeller in front of the plane is equivalent to putting the engine in front of the plane. The engine is very heavy, so putting the engine in the front means that the center of gravity of the aircraft will be forward. In order to ensure the balance and stability of the aircraft, the wings of the aircraft must be designed near the center of gravity. Since the center of gravity of the aircraft is in the front, the wings will naturally be forward. This is the fundamental reason for placing the propeller in front of the aircraft, that is, to make the wings of the aircraft close to the front end of the fuselage, so the propeller is placed in front of the aircraft.

Why are the wings of an airplane closer to the front of the fuselage?

The purpose is to create a distance from the tail wing. The longer the distance, the longer the control arm, so the aircraft is more maneuverable. Placing the propeller at the front of the aircraft can indeed ensure the maneuverability of the aircraft, but it brings a series of problems and hidden dangers. The first problem is low flight efficiency. Propeller aircraft are aircraft that convert engine power into power through propellers, so how to convert it? Of course, it is through rotation to push the airflow backwards, thereby generating a reaction force, but the problem is that there are a lot of obstacles behind the propeller, the aircraft's fuselage, wings, tail, etc., which greatly reduces the thrust of the propeller. Therefore, we will find that any aircraft with propellers placed in the front has large propellers, just to make up for the loss of power by increasing the volume.

The fuselage of the aircraft will block and thus weaken the thrust generated by the propeller. Conversely, the airflow generated by the propeller will also affect the stability of the aircraft. Therefore, propeller aircraft have very high requirements for pilots. Pilots must make adjustments according to changes in airflow during flight to keep the aircraft stable.

So all the planes you see with propellers in the front have a pilot in the cockpit. Are there any planes without a pilot in the cockpit? Yes, such as unmanned reconnaissance aircraft. Now think back to all the unmanned reconnaissance aircraft you have seen on TV, and you will find that there are no propellers in the front of the unmanned reconnaissance aircraft. The propellers are all placed at the back. After all, computers are computers, and programs are programs. It is impossible for them to adjust the flight of the aircraft according to slight changes in airflow like humans, so drones cannot cope with the turbulence disturbances caused by the front propellers.

Placing the propeller at the back of the plane solved all the problems.

There is nothing behind the propeller, so the power conversion efficiency is extremely high. Under the same flight speed, the propeller and engine required for the rear propeller are much smaller, and the airflow blown by the propeller will no longer interfere with the stability of the aircraft fuselage. Since the rear propeller is so good, why not design all propeller aircraft to be rear-mounted? Because the rear propeller actually has more disadvantages. If the propeller is placed at the back, the wing must be placed at the back, so the distance between the wing and the tail is shorter, so the aircraft's maneuverability is reduced.

Placing the propeller at the back of the aircraft means that the airflow generated by the propeller will no longer interfere with the fuselage, but the airflow disturbance caused by the fuselage will in turn affect the propeller.

When the aircraft is flying forward at high speed, the airflow will first hit the fuselage and then enter the propeller. This vibrating airflow will bring a greater impact to the propeller, so the propeller is very easy to be damaged and malfunction. Therefore, the technical difficulty of placing the propeller at the back of the aircraft is actually much higher than placing it at the front. It can be seen that whether the propeller is placed in the front or the back, it is not perfect. The key is to choose the best one based on the purpose of the aircraft. Therefore, fighter jets are mostly equipped with propellers in the front, while unmanned reconnaissance aircraft are equipped with propellers in the rear. So is there any way to have the best of both worlds? Yes, that is, to install propellers at the front and back, so that the strengths of the aircraft can be used to make up for the weaknesses. However, this design will also create a new problem, which is expensive.

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