Glider pilot yaws glider repeatedly to signal ground operator to reduce tow speed. Glider pilot rocks wings to signal ground  operator to increase tow speed. Figure 7-15.  Inflight signals for ground launch. Figure 7-16.  Ground launch tow speed. Tow speed correct: Glider climbs to altitude safely Tow speed too high: Glider cannot rise to climb because doing so would exceed maximum permitted ground launch airspeed Tow speed too low: Glider cannot climb because it is not possible to achieve safe margin above stall speed 7-13