What must a pilot be aware of as a result of ground effect?
A.	Wingtip vortices increase creating wake turbulence problems for arriving and departing aircraft.
B.	A full stall landing will require less up elevator deflection than would a full stall when done free of ground effect.
C.	Induced drag decreases; therefore, any excess speed at the point of flare may cause considerable floating.

Answer (A) is incorrect.
Wingtip vortices are decreased, not increased.

1.5   GROUND EFFECT
Ground effect is the result of the interference of the ground (or water) surface with the airflow patterns about an airplane.
The vertical component of the airflow around the wing is restricted, which alters the wing’s upwash, downwash, and wingtip vortices.
The reduction of the wingtip vortices alters the spanwise lift distribution and reduces the induced angle of attack and induced drag.
Thus, the wing will require a lower angle of attack in ground effect to produce the same lift coefficient, or, if a constant angle of attack is maintained, an increase in the lift coefficient will result.

An airplane is affected by ground effect when it is within the length of the airplane’s wingspan above the ground. The ground effect is most often recognized when the airplane is less than one wingspan’s length above the ground.
Ground effect may cause an airplane to float on landings or permit it to become airborne with insufficient airspeed to stay in flight above the area of ground effect.
An airplane may settle back to the surface abruptly after flying through the ground effect if the pilot has not attained recommended takeoff airspeed.
Ground effect must be considered during takeoffs and landings.
If a pilot fails to understand the relationship between the aircraft and ground effect during takeoff, a hazardous situation is possible because the recommended takeoff speed may not be achieved.
Due to the reduced drag in ground effect, the aircraft may seem capable of takeoff well below the recommended speed. As the aircraft rises out of ground effect with insufficient speed, the greater induced drag may result in marginal initial performance.
In extreme conditions, the aircraft may become airborne initially with insufficient speed and then settle back to the runway.