Today, despite many concerns and immense fears in the mind of man, he tries to choose modern air travel to cover long distances, one of the main reasons being that the journey is quick, calm and safe. Perhaps this is the reason why, according to a certain number, 83 percent of the world's people consider air travel safe.

But despite all these surveys, the question arises here, is it really so? and the same question arises in many human minds whenever an air accident occurs.

Which is sometimes linked to climate changes, technical malfunctions and serious mistakes made by pilots by investigative agencies, one of the few important reasons that has been under scrutiny today is the cause of many accidents since the beginning of air travel.

"Here we would like to inform our respected readers that in the event of any air accident, the first thing that is searched for by the investigation agencies is the black box, which is usually a light orange or red box that stores information related to the flight and the conversations in the cockpit and helps the investigation team in reaching an important conclusion."

As we all know that every machine has a heart and today it would not be wrong to say this. Now the machine also has its own brain, which has been designed to obey human commands. An important part found in an aircraft, the heart of a jet engine is found in its compressor.

COMPRESSOR BLADES

Here, the purpose of this compressor is to create pressure in the air entering the engine before it enters the combustion chamber so that the explosions in the engine can be made more effective and capable of performing the task.

Sometimes, due to some important reasons, this compressor not only affects the ability of the engine to work during flight, but also causes fatal accidents. In technical terms, this is called compressor stall and surge dynamics.

COMPRESSOR SURGE AND STALL CONDITION

Here, in aircraft engineering, stall refers to the condition where there is a sudden decrease in the altitude of the aircraft during flight and conditions such as a severe decrease in air pressure or pressure loss in the engine compressor are called surge.

The stall process in the compressor blades in a jet engine begins when the external air flow or flow demand decreases or increases rapidly due to weather changes, bird strikes, snow accumulation, and any obstruction, and thus a difference is created between the compressor in the engine and the speed, due to which not only severe explosions are heard in the engine, but often in the absence of immediate action, it can cause a fatal accident.

If the stall process in the engine continues as it is, the surge process begins, the stall process can spread in a circle around the annulus.

"The annulus is the space between the rotating rotor and the outer surface of the engine."

During the process, the surge not only causes a change in direction due to the rapidly changing air flow, but also many other conditions are encountered, such as loud explosive sounds, flames coming out of the engine, and a rapid increase in shaft rotation, etc.

All these conditions, in addition to affecting the performance of the engine, have a profound effect on other mechanical parts of the engine, due to which there is a risk of aerodynamic instability.

However, considering all these risks and conditions, today all these complexities have been overcome to a great extent thanks to science, experimental research, computational fluid dynamics and modern control systems, in which the use of full authority of digital engine control systems is common, which not only controls the air pressure ratio, shaft speed and temperature during flight, but also changes the fuel supply, vane angles from time to time so that the compressor can perform its work better and safely.

FADEC

An important feature of the new design being developed for aircraft engines is the use of valves in the compressor blades in the engine, which temporarily remove air from the compressor during the initial stages of the engine or during high speed. This method not only reduces unnecessary air pressure from the engine but also helps in bringing the engine to a stable state in the event of any complications.

In modern passenger aircraft like Boeing and Airbus in use today, thanks to modern research and the tireless work of expert engineers, complications like compressor stall and surge and their resulting accidents have become almost impossible. But this draws our attention to the fact that no matter how powerful the machine, a slight carelessness or a defect in aerodynamics can cause a major accident. Thank you.

Written by Syed Murtaza Hassan