te trim the airplane at point (1) a certain 
amount of up elevator is required and zero 
stick force is obtained~ with’the nse of the tab. 
To trim the airplane for higher speeds corre- 
sponding to points (2) and (3) less and less 
nose-up tab is required. Note that when the 
airplane is properly trimmed, a push force is 
required to increase airspeed and a pull force 
is required to decrease airspeed. In this man- 
ner, the airplane would indicate positive stick 
force stability with a stable “feel” for air- 
246