Why is weight important in aerodynamics?

Weight is a critical factor in aerodynamics because it directly affects the required lift needed for an aircraft to achieve and maintain flight. According to the principles of flight, an aircraft must generate enough lift to counteract its weight to ascend or stay in the air. The lift produced by the wings is a result of the airflow over the wing surfaces, which is influenced by the angle of attack and the relative wind speed.

For any aircraft, as its weight increases, the amount of lift required for level flight also increases. This means that to maintain a steady altitude, a heavier aircraft must either fly at a higher speed or adjust the angle of attack to generate more lift. Consequently, this interplay between weight and lift is foundational to understanding flight dynamics and the necessary performance parameters for any given aircraft design or operation strategy.