Infiniti2000 said:Fang then completes the full-round action to summon a fiendish hawk at 100N80E30Z...
Assuming the lizard remains relatively stationary, Fang will then fly east 30ft, do a wingover, fly back 30ft, do a wingover (so he's in the same spot, heading east), and then cast true strike.
Summoned creatures must be summoned on a surface capable of supporting them (PHB p. 172, second chapter of section on Conjuration). Only creatures that have only a fly speed can be summoned in mid-air. The second sentence is my interpretation, based on the first sentence.
You can only do one wingover per round.