Why do so many planes fly in the sky at the same time and never touch each other?

As people's demand for airplanes has increased, the sky has become more and more crowded and accidents have increased dramatically. On average in Europe, up to 33,000 flights are taken off daily.

Due to the increasing number of flights every day, we are no stranger to news like 'the plane almost collided with each other' or 'the hero pilot who stopped the plane crash'. But in fact, that is almost impossible. Accidents that happen 'close to the ribs' are just a way of saying because such incidents can really be detected from the very beginning.

Flights are controlled at different heights, on different levels.

For example, most recently a "close" collision between Emirates airplanes Airbus A380 and Air Seychelles Airbus A330 from Mauritius to Seychelles. These two planes did not comply with the safety regulations when flying. As a rule: All air vehicles must be separated within 14km and 300m high.

The aircraft tend to fly along a certain street called airways , like streets on the ground. Flights are controlled at different heights, on different levels - called flight levels - to ensure that the two aircraft are never at the same height, and keep a safe distance around .

The air traffic unit also has a radar system and a computer system that helps keep aircraft away from each other when taking off, landing, changing height or changing routes. In the above case, the Emirates crew misunderstood the air traffic controller's instructions and began flying into the Air Seychelles flight route, while the air traffic controller did not point the other way.

Pilots, air traffic control stations, maintenance staff and all other people involved in air transport sometimes make mistakes but it is extremely rare. Safety has gradually increased, from 12 deaths / 10 million flights in 2006, to four in 2016. Everyone working in the aerospace industry must be skilled and well trained. kidneys and above all, the technology used to coordinate aircraft is very sophisticated and can quickly overcome human errors.

In the above case, the traffic collision avoidance system is equipped in both aircraft to quickly discover mistakes and guide both crews to adjust their flight routes. This will never be a " narrow escape" because the closest distance between two planes is 14km and there are more than 30 seconds of warning since any risk of remote collisions. This is definitely not a ' scandal ' incident .

Early warning diagram of aircraft crash.

Since the early 1990s in the United States and since 2000 in Europe, passenger aircraft cannot fly without the Traffic Collision Alert System (TCAS) . This is a relatively simple but intelligent radar system that avoids unfortunate accidents. The aircraft constantly updated its position via radio waves, along with some other information such as altitude, speed and direction. If the plane's TCAS receives a signal from another aircraft, it will start a conversation with other planes, find out how far apart they are based on the time it takes to receive a response.

The system will determine what information other aircraft come from through the antenna system and then calculate dangerous situations. It also comes with a display of aircraft around so that the pilots can monitor the situation. If an aircraft is about to cross the safety zone of another aircraft, the two TCAS units start working to come up with a solution. The first turn, usually 20 to 48 seconds compared to the risk of collisions, the pilots of both aircraft will hear a related voice warning "traffic flow!" In the cockpit. The crash plane will be displayed in yellow on the screen and the pilot will usually start looking outside to find light or clues. As the two planes get closer - within 20 to 25 seconds before the collision - TCAS offers "settlement advice". It automatically coordinates smoothly with other aircraft units and other systems for pilots to know what to do: lower, climb or change other routes.

Pilots are trained to follow the instructions of TCAS even if it conflicts with the air traffic controller. Because it is mainly because the system responds and makes decisions much faster. One of the direct causes of the notorious Überlingen collision created southern Germany in 2002 - of which 71 were killed - because one of the two teams did not follow the TCAS guidelines but followed the controller's order. save.

Pilots are trained to follow the instructions of TCAS even if it conflicts with the air traffic controller.

The TCAS system never gives instructions for non-fonts to turn, only to fly high or lower. But if the pilot finds that the aircraft is about to collide, they must turn right under the law. The plane's direction is easy to detect: the left wing has a red light and the right wing has a green light. The planes cross right to left with the road and show red light for other planes to see. People who go from left to right will see a green light. It is a basic visual system, so pilots can react properly in the worst case.

Chances are that when the pilot of Air Seychelles flies receives an advice from TCAS, he decides to turn to the right to watch out after seeing other aircraft lights. As said, the minimum distance between the two planes is about 14 km after turning, the 30-second safety time has been recorded, even taking into account that they fly about 850km / h.

'Death smoking' situations will not happen if it has been warned in advance. The aviation industry is constantly looking for solutions to improve safety standards so aircraft crash accidents will always be a top priority in ensuring passengers' lives.