When in ground effect, what primarily allows for greater lift?

The primary reason that allows for greater lift when in ground effect is due to decreased induced drag. Ground effect occurs when an aircraft is close to the ground, typically within one wingspan’s distance. In this condition, the airflow around the wings is altered due to the proximity of the ground, which helps to reduce the strength of the wingtip vortices that normally form as the aircraft generates lift.

These vortices are a significant contributor to induced drag, which is the drag that occurs as a byproduct of lift generation. When an aircraft is at a low altitude, the reduced interference from the ground allows the wings to operate more efficiently, leading to an increase in lift without a corresponding increase in induced drag. This is particularly beneficial during takeoff and landing phases, as it allows the aircraft to become airborne at lower airspeeds and requires less power to maintain flight.

The other options, while they may have an impact on flight characteristics, do not directly explain the specific mechanics of increased lift experienced in ground effect. Increased weight distribution does not inherently lead to greater lift, increased angle of attack can lead to stall risks, and lower power requirements relate to engine efficiency rather than direct lift generation.