What is the primary effect of increased angle of attack up to the stall angle?

Increasing the angle of attack (AoA) up to the stall angle primarily increases lift due to the way airflow behaves over an airfoil. As the angle of attack is raised, the shape of the wing directs airflow in a way that enhances pressure differences above and below the wing. This pressure differential generates more lift, as long as the angle does not exceed the stall angle.

At moderate increases of the angle, the airflow remains attached to the wing's surface, allowing it to effectively funnel air and produce a greater upward force. However, it's essential to recognize that this increase in lift is only valid up to the critical stall angle. Beyond this point, if the angle continues to increase, airflow may separate from the wing surface, leading to a decrease in lift and the onset of a stall condition, where control and performance of the aircraft can be severely compromised.

The other options do not accurately reflect the impact of increased angle of attack. While increased AoA does have complex effects on drag, it typically does not decrease it; instead, drag usually increases as lift increases. The angle of attack does not influence the aircraft’s weight, which is a separate factor determined by the mass of the aircraft and its load. Similarly, the thrust generated by the engines is