Learn something new – the stages of sailing

There is a game between China and the United States in the past few days. It is probably that the airlines of country M want to apply to resume flights. The relevant departments did not agree at first, but then Country M became angry and said that if you don't let me fly, then none of us will fly... So it issued a flight ban. Later, probably a few hours later, we agreed again and just said you can fly...and then reversed it again!

When classmate Xiaoli heard the news, she felt very excited. After all, there were many more airline flights, and then she said, it’s time to start air navigation! In fact, general aviation is not that simple. Although the demand is now very high, the tickets may be sold out as soon as they are released. However, the flight of an airplane is not just about selling tickets. It involves many aspects, including the operation of the airplane. Maintenance, pilot preparation, flight attendant preparation, cargo logistics, airport preparation, etc... In short, aviation flight is a complex system engineering, which requires many prerequisites and requirements. Just say it! Not to mention the airlines, if we drive a long distance, we probably have to prepare a lot, check the tire pressure, check the brakes, even perform maintenance on the car, and then purchase various things before we can set off, not to mention... Such a big plane can fly such a long distance, halfway around the world.

Okay, without further ado, let’s learn some new knowledge today and talk about the stages of aviation flight. Simply put, aviation flight can be roughly divided into 8 stages.

On ground / Preflight

Taxing

Takeoff and Departure

Climb.

Cruise stage.

Decline stage, descent.

Approach phase approach.

Landing stage.

Strictly speaking, this stage is not a stage of flight. It is probably the various preparations made by the aircraft before the flight, such as refueling and overhauling the aircraft, allowing passengers to board the aircraft, etc., so we sometimes It's called paragraph 0. At this stage, the plane is fixed on the ground, and basically the engine is not on the corridor, or some shuttle buses will connect here. On the plane, there is also some cargo, and some maintenance personnel are knocking on it. beat. So this section is called the pre-flight section or the ground. After all, the aircraft still has to deal with many things on the ground before taking off.

The first stage is taxiing, which is probably after the aircraft is loaded with people and cargo and everything is ready, so you can consider taxiing to the runway. The aircraft has entered the airside stage since it left the corridor. The so-called airside means that the aircraft can enter the operational stage. The so-called ground survey is actually a stage where the airport and airlines, such as passenger logistics, etc., are completed together. During the air test phase, the aircraft was managed by air traffic control, which means that the forward takeoff of the aircraft at this time is not decided by the airline, but is decided by air traffic control. Therefore, from the moment the aircraft leaves the corridor and starts taxiing, it enters the airside. There is a critical time called the wheel gear time. When the aircraft is on the corridor, there are several wheels to fix the aircraft under it. The party is called wheel chock, just like when we park the car on a hillside, we will put a brick behind the wheel. The principle is the same. When the wheel chock is removed, it means that the aircraft can move, so it enters taxiing and taxis on the taxiway. , and then gradually taxi to the runway end. At this time, the taxiing phase is over and the taxiing phase may be waiting, some maintenance may be performed, and some de-icing operations may be performed if the weather is too cold. If we fly in winter or on snowy days, we will find vehicles similar to fire trucks spraying spray on the plane. This is de-icing.

After taxiing, the aircraft reaches the end of the runway and is ready to enter the take-off phase, that is, taxiing on the runway.

When taxiing on the runway, there is also a flight gap. The two planes cannot be too close to each other. In addition to not really colliding, there is also the impact of wake turbulence. After the previous plane flies over, the same large ship will pass by. There will be some wave effects later. Therefore, there is an interval between aircraft. Generally speaking, the interval between ordinary aircraft is about one and a half to three minutes, depending on how big the aircraft is. The largest Airbus A380 should theoretically have an interval of three minutes, but When we are running, for the sake of safety, we usually give it a 10-minute interval, which means that after a 380 takes off, there will not be a second plane taking off on this runway within 10 minutes.

At this stage, the aircraft will accelerate and taxi from the end of the runway until it leaves the ground, so it is called takeoff, also called take off.

The plane has just taken off. It can only be regarded as the ground it has just left. It will fly higher and higher, so it must climb. It is probably the plane that has to climb to a height that can fly normally. Generally speaking, the flight of the plane The altitude is about 10,000 meters. We have a song called the distance of 30,000 feet. One foot is about the same as our one foot. It is about 10,000 meters when converted. In other words, the plane has to gradually climb from the ground to 10,000 meters. Meter altitude, this stage is called climb, because the plane is rising diagonally and it has to pass through different levels, so it forms a three-dimensional traffic at this time.

The cruise phase is the period during which the aircraft flies the most. When the aircraft climbs to a certain altitude, it starts cruising. In fact, it is different from what we imagined. When the aircraft is flying, its altitude is strictly controlled. Limited, every 1,000 feet in the air. It's about 300 meters. Don't ask what it is in feet. It's determined by the Americans, because they use feet. Whoever sets the rules has the final say. Every 1,000 feet apart, the plane can have another one. Another level is equivalent to having another lane. However, they can fly in the same direction only every 2,000 feet apart. In order to ensure that they do not intersect, in fact, every 1,000 feet, one is flying south and the other is flying north, which means that there are interspersed flying in the opposite direction. This is called flying. height level.

When airplanes fly in the sky, there is a gap between them. The gap is different under different conditions. It is different from what we think. Aircraft are actually not as advanced as we imagined. They don’t even have GPS navigation. What they use is called radar monitoring. There was even program monitoring before. The so-called program monitoring is to calculate the time based on the speed of the aircraft, how long it can fly and how far it can fly, so as to control how far the aircraft can fly in the air. , and radar surveillance is more powerful first. You can see aircraft through radar. Radar was probably invented during World War I or World War II, and it is still less than 100 years ago. But for GPS or car navigation equipment, it is already an old story, but radar control has not been fully realized in China. In the case of radar control, the approximate interval is 18 kilometers. Why is it 18 kilometers? Because 18 A kilometer equals 10 nautical miles, why nautical miles? It’s still the same as the previous one, because the rules are set by everyone. This also shows from another aspect that in fact, we still have shortcomings in many places, and we are still following others.

For procedural control, the interval is even greater. Generally, the interval is 15 minutes. That is to say, if a plane flies over, another plane will arrive after 15 minutes. The cruising speed of the plane is about It is 800~900 kilometers, which is about 150 kilometers in 15 minutes. Unfortunately, our planes fly slowly in the sky at such a large interval, so we always complain that our airspace is not enough and the planes are constantly delayed, so much so that even if you apply for delay insurance, you will be taken away. In fact, we still have a lot of room to compress.

After the flight, the plane will descend. The descending stage is called dissent.

In fact, the descent of the aircraft is different from what we imagined. It is one section at a time, so we call it gradient descent, which means descending for a section, stopping for a section, and then descending for the next section. This is because at the beginning everyone They also don’t know the status of the aircraft, so the aircraft needs a certain amount of time to adjust, and it just descends step by step. Recently, navigation equipment has been enhanced, its operating capabilities have also been improved, and computer technology has also advanced, so people I was wondering if I could finish the descent in one fell swoop. In this way, I would plunge down from a high altitude without having to adjust it back and forth. It would also save me the tension. After all, the equipment supports it. This method is called continuous descent. I tried it in Tianchao and finally it seemed like failed. The specific reason is another story.

Approach is a very magical word called approach. It roughly means getting close, which means that the aircraft has finished descending and is now ready to align with the runway and prepare to land. This process is called approach. There is a device on the ground called an instrument landing system, and there is a set of flight procedures on the aircraft called an instrument approach procedure. It is to tell the aircraft how to approach the airport runway and prepare for landing when it approaches the airport. A lot of equipment comes into effect at this time to guide the aircraft to constantly calibrate its position. As for why, during the flight, if we make statistics on each stage of the flight, then there will be nearly 1/3 to half of the flight accidents. It happens at this stage. This also shows from another side that this stage is indeed very dangerous and the operation is particularly complicated, which is why everyone is willing to invest some technical power here.

The instrument landing system is actually two sets of radios. One determines its horns and the other determines its orientation to determine whether the aircraft is correctly aligned with the runway. The angle is fixed. If the aircraft enters By following this route, it can be guaranteed that he will be in contact with the runway line at the final place and landing point, that is, a complete landing will be completed.

After the aircraft completely sees the runway, there is a place called the final decision height. That is, if the pilot cannot see the runway at this time, he still has a chance to pull the aircraft up. This height is usually It is about 300 feet. The specific situation depends on the obstacles around the airport. You can imagine the surrounding area. If there are mountains, then the height must be higher. If it is a flat plain, it may be lower. After all, the pilot still has Some collaborative action time. When we get here, we usually rely on the pilot's eyes to confirm the landing. In other words, we still have to rely on the pilot's eyes to complete the final step of the landing. Although our instrument navigation system can now reach Level 3 standards, which means that it can There are still some differences in achieving a blind landing without pilot participation. At least there are many places where the equipment and navigation conditions may be available, but the controllers, pilots and ground guidance service personnel do not have this ability, or have not gone through specialized procedures. The training cannot be implemented. This also lets us know that although there are some technical solutions, there are still some far-reaching capabilities. For example, training and the like need to be kept up before they can be used.

Ha, that’s it for today’s daily update. I just find a picture when I have nothing to do, and then continue to compile it... I will update it daily and learn some new knowledge. It is not professional, just a casual introduction.