Have you ever wondered how high a plane can fly when it flies across the sky with a long trail?
Generally speaking, two conditions need to be met for the flight of an aircraft. The wings generate lift to overcome their own gravity, and the engine generates thrust to overcome their own resistance.
According to the formula of lift force, in order to keep the lift force always equal to the gravity force to maintain level flight, the aircraft must increase the flight speed, which will inevitably bring greater flight resistance, thus requiring the engine to generate greater thrust.
When the aircraft reaches a certain altitude, the air density decreases and the oxygen concentration decreases, so that the fuel in the engine burns insufficiently, and the limit thrust of the engine decreases to equal to the flight resistance. When the aircraft can no longer be accelerated, the aircraft reaches the theoretical maximum. high.
There is a big difference in the maximum flight altitude of aircraft with different volumes and different functions. For example, my country's domestically produced large aircraft C919 has a maximum flight altitude of 12,100 meters, the large transport aircraft "Kunpeng" Yun-20 has a maximum flight altitude of 13,000 meters, and the foreign Airbus A320 passenger aircraft has a maximum flight altitude of 12,000 meters.
As for the maximum flight altitude of fighter jets, my country's carrier-based J-15 fighter jets reach 20,000 meters, and the US F-35 fighter jets reach 18,288 meters. At present, the flying altitude record of human aircraft is the 108,000-meter altitude achieved on August 22, 1963, created by the X-15 verification aircraft of the United States.
So, is it necessary for the aircraft to reach this flight altitude during flight? The answer is of course no.
In the actual flight of a civil aviation airliner, due to the need to consider fuel consumption, engine temperature limitations, voyage length and air control requirements, the flight altitude is usually lower than the maximum altitude, and it flies in the top of the troposphere and the stratosphere at about 10,000 meters. Flying at this altitude, the aircraft is stable and saves fuel, and has good economy.
For fighter jets, due to combat needs, the maximum height has greater significance. Flying high and widening the field of vision, it is easier to be in a better combat position, and the combat ability is relatively stronger. Usually fighter jets fly at a much higher altitude than civil aviation airliners after entering combat. The second-generation fighter jets pursuing high altitude and high speed, represented by the Soviet MiG-25, have a maximum flying altitude of 37,650 meters.
The third and fourth generation fighter jets pursue comprehensive performance, not simply pursuit of flying height. Such as J-15, F-16 and other third-generation fighters are generally at 15,000 to 20,000 meters. The ceiling of the fourth generation fighter such as F-22 is about 19812 meters.
The above mentioned are all fixed-wing aircraft. For helicopters that rely on rotors to generate lift, civil helicopters generally have a ceiling of 2000-4000 meters, and military helicopters can reach 6000 meters. For example, the American "Apache" gunship can fly to about 6250 meters.
From the Low Flight of the Wright Brothers' First Plane
Up to now, the plane has easily broken through the altitude of 10,000 meters
Human yearning and exploration of the sky have never stopped
With the rapid development of technology
Aerospace integrated aircraft may also appear in the future
That's when we'll really break through the height limit
Fly out of the atmosphere to travel the bright galaxy
