What is the acute angle formed by the chord line of a wing and the relative wind called?

The acute angle formed by the chord line of a wing and the relative wind is referred to as the angle of attack. This is a crucial concept in aerodynamics, as it directly affects the lift generated by the wing. When a wing has a certain angle of attack, it influences how the air flows over and under the wing, which can lead to varying lift characteristics.

As the angle of attack increases, the lift typically increases up to a certain point known as the critical angle of attack. Beyond this angle, the airflow can start to separate from the wing's surface, leading to stall conditions where lift dramatically decreases. Understanding the angle of attack is vital for pilots and engineers when assessing aircraft performance and stability.

The other terms referred to in the question represent different aerodynamic concepts. The angle of incidence refers to the fixed angle between the wing's chord line and the longitudinal axis of the fuselage, not the relative wind. The angle of bank relates to how much an aircraft is tilted during a turn, and the angle of descent refers to the path of the aircraft as it descends, neither of which are directly connected to the interaction between the wing and the relative wind in the same way as angle of attack.