Airplane landing and take-off speed - parameters calculated individually for each liner. There is no standard value that all pilots must adhere to, because aircraft have different weights, dimensions, and aerodynamic characteristics. However, the speed value during landing is important, and non-compliance with the speed limit can turn into a tragedy for the crew and passengers.
How is take-off?
The aerodynamics of any liner is provided by the configuration of the wing or wings. This configuration is the same for almost all aircraft except for small parts. The lower part of the wing is always flat, the upper is convex. Moreover, the type of aircraft does not depend on this.
The air that, under speed, passes under the wing, does not change its properties. However, the air, which at the same time passes through the upper part of the wing, narrows. Consequently, a smaller volume of air passes through the upper part. This leads to a pressure difference under and above the wings of the aircraft. As a result, the pressure above the wing decreases, under the wing it rises. And it is precisely due to the pressure difference that the lifting force is formed, which pushes the wing up, and together with the wing, the aircraft itself. At that moment, when the lifting force exceeds the weight of the liner, the plane takes off from the ground. This occurs with an increase in the speed of the liner (with increasing speed, the lifting force also increases). Also, the pilot has the ability to control the flaps on the wing. If you lower the flaps, the lifting force under the wing changes the vector, and the plane gains altitude sharply.
It is interesting that an even horizontal flight of the liner will be provided if the lifting force is equal to the weight of the aircraft.
So, the lifting force determines at what speed the plane takes off from the ground and starts flying. Also plays the role of the weight of the liner, its aerodynamic characteristics, engine traction.
Aircraft speed during takeoff and landing
In order for a passenger plane to take off, the pilot needs to develop a speed that will provide the required lift. The greater the acceleration speed, the higher the lifting force. Therefore, with a high speed of acceleration, the aircraft will take off faster than if it were moving at a low speed. However, the specific speed value is calculated for each liner individually, taking into account its actual weight, degree of load, weather conditions, runway length, etc.
Generally speaking, the well-known Boeing 737 passenger airliner comes off the ground when its speed grows to 220 km / h. Another famous and huge Boeing 747 with a large weight comes off the ground at a speed of 270 kilometers per hour. But the smaller Yak-40 airliner is able to take off at a speed of 180 kilometers per hour due to its light weight.
Takeoff types
There are various factors that determine the speed when taking off an aircraft liner:
- Weather conditions (wind speed and direction, rain, snow).
- The length of the runway.
- Strip coating.
Depending on the conditions, takeoff can be carried out in different ways:
- Classic speed set.
- With the brakes.
- Take-off using special means.
- Vertical climb.
The first method (classic) is used most often. When the GDP is of sufficient length, the aircraft can confidently gain the required speed necessary to provide high lift. However, in the case where the length of the GDP is limited, the aircraft may not have enough distance to set the required speed. Therefore, he stands for some time on the brakes, and the engines are gradually gaining traction. When the thrust becomes large, the brakes are released, and the plane abruptly breaks away, quickly gaining speed. Thus, it is possible to shorten the take-off path of the liner.
About vertical take-off is not necessary. It is possible in the case of special engines. And take-off using special means is practiced on military aircraft carriers.
What is the speed of the aircraft when landing?
The liner does not sit on the landing strip right away. First of all, there is a decrease in the speed of the liner, a decrease in height. First, the plane touches the runway with the wheels of the chassis, then it moves at high speed already on the ground, and only then it brakes. The moment of contact with GDP is almost always accompanied by shaking in the cabin, which can cause concern for passengers. But there is nothing wrong with that.
The speed during landing is practically only slightly lower than during take-off. Large "Boeing 747" when approaching the runway has an average speed of 260 kilometers per hour. This speed should be in the liner in the air. But, again, the specific speed value is calculated individually for all liners, taking into account their weight, workload, weather conditions. If the plane is very large and heavy, then the landing speed should be higher, because when landing it is also necessary to "hold" the required lift. Already after contact with the GDP and while moving on the ground, the pilot can slow down the means of landing gear and flap on the wings of the aircraft.
Flight speed
The speed during landing and take-off is very different from the speed at which the aircraft moves at an altitude of 10 km. Most often, airplanes fly at a speed that is 80% of the maximum. So the maximum speed of the popular Airbus A380 is 1020 km / h. In fact, the flight at cruising speed is 850-900 km / h. The popular Boeing 747 can fly at a speed of 988 km / h, but in fact its speed is also 850-900 km / h. As you can see, the flight speed is fundamentally different from the speed when landing the aircraft.
Note that today the company is developing a Boeing airliner, which can gain flight speed at high altitudes up to 5000 kilometers per hour.
Finally
Of course, landing speed is an extremely important parameter that is calculated strictly for each liner. But you can not name the specific value at which all planes take off. Even identical models (for example, Boeing-747) will take off and land at different speeds due to various circumstances: congestion, the amount of fuel refueling, the length of the runway, covering the strip, the presence or absence of wind, etc.
Now you know what the speed of the aircraft is during landing and when it takes off. Average values are known to all.