An airplane leaving ground effect will experience which of the following changes?

An airplane leaving ground effect will experience which of the following changes?

• A. Increase in induced drag and require more thrust
• B. Decrease in induced drag and require less thrust
• C. Increase in wing lift only
• D. No change in thrust or drag

Answer: (A)

Leaving ground effect removes the ground’s dampening influence on wingtip vortices and downwash. In ground effect, induced drag is reduced because downwash is lower and the wing operates with a more favorable pressure distribution. When you climb out of that zone, downwash increases and the wingtip vortices are stronger again, so induced drag rises. Higher drag means more thrust is needed to maintain the same speed and flight condition. Although lift can also decrease a bit as you leave ground effect, the change described here most directly matches the increase in induced drag and the corresponding need for more thrust.

Leaving ground effect removes the ground’s dampening influence on wingtip vortices and downwash. In ground effect, induced drag is reduced because downwash is lower and the wing operates with a more favorable pressure distribution. When you climb out of that zone, downwash increases and the wingtip vortices are stronger again, so induced drag rises. Higher drag means more thrust is needed to maintain the same speed and flight condition. Although lift can also decrease a bit as you leave ground effect, the change described here most directly matches the increase in induced drag and the corresponding need for more thrust.