What is flight control engineering and how is it contributing to the development of modern aircraft and future transportation?

This article explains the concept and importance of flight control engineering, covering the evolution and potential applications of the technology with examples ranging from paper airplanes to state-of-the-art aircraft such as the B-2 and F-35. It also explores how control technology can be applied not only to aircraft, but also to a variety of future technologies such as self-driving cars, drone delivery systems, and more.

 

Take out a piece of A4 paper. If you folded it in half to make a paper airplane, would it fly well? Without even trying, the answer is obvious. It wouldn’t fly. The paper airplane lacks basic flight stability. However, if you apply flight control engineering to this simple paper airplane, the story is different. Even a paper airplane has the potential to fly freely in the sky. In this article, we’ll take a closer look at what flight control engineering is, how it can make unstable aircraft fly stably, and what new possibilities it opens up.
The importance of flight control engineering is not only about the safety of an aircraft’s flight, but also about maximizing its performance and efficiency. Especially in highly technical fields such as military aircraft, flight control engineering is no longer an option, but a necessity. As technology advances, flight control systems are becoming more sophisticated, enabling aircraft to perform increasingly complex missions.
To understand how flight stability works, let’s take a more specific look at why the paper airplane above lacks flight stability. There are four forces that act on an airplane: lift, gravity, drag, and thrust. Lift is the force that tries to lift you up, while gravity is the force of the earth pulling you down. In general, lift increases with speed. Drag is the force of the air against the aircraft, which prevents it from moving forward, and thrust is the force of the engine, which tries to propel it forward. The center of gravity for each of these four forces is usually different.
For example, consider the interaction of lift and gravity. Imagine that the point of lift is ahead of the point of gravity. Lift acting on the front of the aircraft will lift the front of the aircraft, while gravity acting on the back will pull the back of the aircraft down. As a result, the aircraft and its attached wings will lift upward. As the wings lift upward, the area of contact between the air and the wings increases, which increases drag. A stable paper airplane will slow down due to drag, which reduces lift. As the lift decreases, the rotational force also weakens, returning the airplane to its original state. On the other hand, the large wing area of the paper airplane in the example creates a very large amount of drag, which reduces its speed too much and causes it to lose lift. An airplane that loses lift will eventually crash.
Here we can imagine. What if we had a computer, sensors, and motors that were light enough to be attached to a paper airplane? This would allow the airplane to fly without crashing. You could attach a small control surface to the back of the wing that moves up and down, so that when the airplane goes up, you can raise the control surface to point the airplane down, and when it goes down, you can lower the control surface to point the airplane up. This changes the airflow around the airplane, shifting the point of lift. If you can do this quickly and precisely, without stopping, you can achieve stable flight. Performing this sequence of actions is called “flight control engineering”. In short, flight control engineering is the art of relating inputs and outputs. The controller takes the attitude of the aircraft obtained from the sensors and the desired movement of the user, and sends out an output that moves the engine or control surface to reduce the difference between the two. The key to a good controller is how it determines the output value for the input. The designed controller is simulated in a computer model and then implanted into the aircraft’s computer.

 

 

There is an aircraft that some people refer to as an “iron” due to its flat shape. The B-2, a bomber developed by Northrop Grumman in 1988, is an example. It is famously scrambled from a U.S. Air Force base in Hawaii in response to North Korea’s provocations. Aircraft with wings that are fuselages themselves, like the B-2, are called “flying wings”. Flying wings are older than you might think. They’ve been around since the 1930s, with the Nazis trying to build them. However, none of the flying wings attempted before the B-2 were commercialized. This is because they were unable to fly properly due to stability issues like the ones described in the previous example. The lack of a vertical tailplane on a commercial airplane, which, unlike a paper airplane, has to change direction, was even more fatal. Nevertheless, aeronautical engineers didn’t give up on the idea of a flying machine because of its unique advantages. The flying machine boasted stealth (the ability to avoid radar detection) and flight efficiency unlike any other form of airplane. Their large fuselage area also allowed them to carry large amounts of bombs and cargo.
It wasn’t until the 1980s, more than 50 years after the first fighter jet, that advances in control technology made it possible to develop a viable fighter jet. The B-2 utilized a form of control called fly-by-wire (FBW). The name comes from the fact that the plane flies by wires that carry electrical signals. Whereas the pilot would have had to manually steer the controls via hydraulics, with FBW, the pilot gives commands to a computerized controller for direction and speed, and the controller uses these values to make the optimal maneuvers to keep the aircraft stable. This FBW technology constantly moves the control surfaces to keep the airplane steady, even during level flight. Before FBW, pilots had to do this constantly, and due to the unstable structure of airplanes, any mistake could be catastrophic.
Today’s modern airplanes are all products of control engineering, which has become one of the most important aspects of aircraft design. The F-35, currently under development by American aircraft manufacturer Lockheed Martin, has 15 million lines of control software, with software development alone accounting for 40% of the total development cost. The reason why companies are rushing to invest in control technology is not necessarily because of the unique shape of the aircraft, such as the B-2, but because the application of control technology opens up more possibilities, such as improved maneuverability and stability.
Advances in control technology aren’t just about improving existing aircraft. New types of aircraft are constantly being created. The quadrotor, which you may have seen as a toy recently, is also a result of advances in control technology. As its name suggests, a quadrotor is an airplane that flies freely using only four motors and propellers. Stabilizing a quadrotor is like balancing a pole on your fingertips. But with the help of control technology, it’s easy to get it airborne. Quadrotors are gaining attention for their simple structure of a skeleton, motor, and propeller, and in June of last year, Domino’s Pizza in the UK released a video of a pizza delivery using a quadrotor. There are many other new types of aircraft that utilize control technology. The rapidly evolving world of flight control engineering is a good indication of how far aviation technology can go in the future.
Advances in flight control engineering aren’t just limited to airplanes. It has the potential to be applied to the future of transportation and other aspects of human life. For example, the principles of flight control can be applied to autonomous vehicles, drone delivery systems, or various automation systems in smart cities. This wide range of possible applications makes flight control engineering not just about controlling aircraft, but an important technology for solving a wide range of future problems.
In conclusion, flight control engineering is the pinnacle of modern technology, allowing humans to fly safer and more efficiently and to develop new forms of transportation and logistics. The advancement of flight control engineering will not stop in the future, and we should pay attention to the new possibilities it will create.