FAA Ground School Practice Test

In aviation, what does the acute angle (denoted as 'a') typically refer to?

1. Vertical speed

2. Rate of climb

3. Angle of attack

4. Flight path angle

The correct answer is: Angle of attack

In aviation, the acute angle often refers to the angle of attack. This is a critical concept because the angle of attack represents the angle between the wing's chord line and the oncoming airflow or relative wind. It is directly related to the aircraft's performance, specifically its lift and stall characteristics. When the angle of attack increases, the lift generated by the wing also increases to a certain point, beyond which the airflow begins to separate from the wing, leading to a stall. Understanding the angle of attack is essential for pilots to maintain safe flight conditions, manage lift effectively, and ensure that the aircraft can respond correctly to aerodynamic forces. The other options represent different aviation concepts. Vertical speed refers to the rate at which the aircraft ascends or descends. Rate of climb specifically measures how quickly an aircraft gains altitude over time. Flight path angle, on the other hand, describes the angle between the horizon and the aircraft's trajectory, indicating whether the aircraft is climbing, descending, or flying level. Each of these concepts is important in aviation but does not match the specific definition of the acute angle as the angle of attack does.