What do flaps primarily alter to improve take-off performance?

Flaps primarily alter the wing camber to improve take-off performance. When flaps are extended, they effectively increase the curvature of the wing's upper surface. This increased camber enhances the lift characteristics of the wing at lower speeds, allowing the aircraft to generate sufficient lift during takeoff even as it operates in a slower speed range. This is particularly important during takeoff, as it enables the aircraft to become airborne at lower airspeeds and reduces the required runway length for takeoff.

In addition to improving lift, flaps can also contribute to better control and stability during the takeoff phase. The increased lift allows for a shorter takeoff roll, which can be crucial in various operational conditions, such as high-altitude runways or scenarios where runway length is limited. The other choices, such as wing aspect ratio, wing area, and wing weight, do not directly influence take-off performance in the same way that wing camber does when flaps are deployed.