 Fixed wing aircraft

When an aircraft flies at a ground level approximately at or below the half length of the aircraft's wingspan there occurs, depending on airfoil and aircraft design, an often noticeable ground effect.This is caused primarily by the ground interrupting the wingtip vortices and downwash behind the wing.When a wing is flown very close to the ground, wingtip vortices are unable to form effectively due to the obstruction of the ground.