IL.VII.A.K4

From the FAA library

• Pilot's Handbook of Aeronautical Knowledgep. 5-11
  Chapter 5: Aerodynamics of Flight › Ground Effect

  Figure 5-16. Ground effect changes airflow. Ground effect also alters the thrust required versus velocity. Since induced drag predominates at low speeds, the reduction of induced drag due to ground effect will cause a significant reduction of thrust required ... downwash, and wingtip vortices, there may be a change in position (installation) error of the airspeed system associated with ground effect. In the majority of cases, ground effect causes an increase in the local pressure at the static source…

• Pilot's Handbook of Aeronautical Knowledgep. 11-15
  Chapter 11: Aircraft Performance › Takeoff and Landing Performance › Takeoff Performance

  takeoff or landing distance as a function of the ratio of wind velocity to takeoff or landing speed. The effect of proper takeoff speed is especially important when runway lengths and takeoff distances are critical. The takeoff speeds specified ... very low initial ROC. In some cases, an excessive AOA may not allow the aircraft to climb out of ground effect. On the other hand, an excessive airspeed at takeoff may improve the initial ROC and “feel” of the aircraft…

• Airplane Flying Handbookp. 6-10
  Chapter 6: Takeoffs and Departure Climbs › Ground Effect on Takeoff

  Ground Effect on Takeoff Ground effect is a condition of improved performance encountered when the airplane is operating very close to the ground. Ground effect can be detected and normally occurs up to an altitude equal to one wingspan above ... surface. [Figure 6-7] Ground effect is most significant when the airplane maintains a constant attitude at low airspeed at low altitude (for example, during takeoff when the airplane lifts off and accelerates to climb speed, and during the landing…