angle of attack. However, as can be noted 
from the curves of figure 6.6, small deviations 
from the optimum C, will not cause a drastic 
reduction of (L/D) and glide ratio. In fact, a 
5 percent deviation in speed from the best glide 
-4 VT- w, VI w, (constant C,> 
where 
VI= best glide speed corresponding to 
some original gross weight. WI 
V,=best glide speed corresponding to 
some new gross weight, IV2