To be fully precise, though at the risk of getting too arcane, I'll
point out that the "shift the polar" treatment for the effect of wind on
STF only gives the true airspeed
_component_in_the_direction_of_the_track. The true "airspeed to fly"
also depends upon the cross-wind component of the wind, since one must
crab to fly the desired track. The effect of this additional factor is
typically small, less than 3 kts. In my previous example calculation I
used a cross-wind component of zero to make things simpler.

Jack