Which of the following is not considered practice of aeronautical engineering?

The practice of aeronautical engineering encompasses a variety of activities directly related to the design, development, and testing of aircraft and spacecraft. Each of the activities listed informs how engineers operate within the field.

Designing an aircraft structure is a fundamental aspect of aeronautical engineering, as it involves applying engineering principles to ensure the safety, durability, and performance of the aircraft under various conditions.

Teaching Aerodynamics also falls under the purview of aeronautical engineering because it involves imparting knowledge about the principles and behaviors of airflows affecting aircraft, which is crucial for understanding and advancing aeronautical practices.

Flying an airplane, however, is considered a piloting skill rather than an engineering practice. While understanding how to operate aircraft is important for engineers, the act of flying does not involve the engineering design and analysis processes that characterize aeronautical engineering. Thus, it is distinct from the engineering practice itself.

In summary, the correct choice identifies an activity that, while related to aviation, does not encompass the technical and design elements intrinsic to aeronautical engineering.