Yes and NO! Part of your training is in the aircraft where you will learn to move the flight controls and technically learn how to fly. You will take off, make the aircraft go up or down, make it turn left or right, and make it land safely. However, the knowledge you learn in Ground School by reading and studying books, working in groups, and participating in demonstrations and discussions provides the basis for your competence as a commercial pilot. This is not information you learn and then forget. This true knowledge that forms the basis of your pyramid with your airline pilot career at the pinnacle. If all you can do is manipulate the controls, you will be a danger to everyone in aviation. If you learn all the information covered in Ground School, you will be an asset to the field of aviation. Ground School teaches you about weather, navigation, communication, and how and why the controls work. All of this knowledge together ensures your competence as a skilled pilot who not only flies the plane but is able to fly safely in every situation.