Hawkman (vol 1) #24 VG

Assigned to protect General Foster, who is to preside over an Armed Services Day parade, Hawkman notices that the general salutes with the wrong hand, exposing him as a robot impostor. Other military leaders and his own wife have been similarly replaced, and Katar tracks Shayera through space. He arrives on a sunless planet, and is set upon by winged beasts, which he defeats with his refrigeration. Disguising himself as a robot, he infiltrates, but is easily detected, and he and Shayera are united at gunpoint. They learn of this world's plan to invade Earth, and are then forced into combat with beasts in an arena. They escape, find the Earth leaders, and return home, as Katar discovers that there is no argon in the invading planet's atmosphere. Hawkman leads the defending army when the aliens invade, commanding a flock of bomb-laden birds, until he is wounded and given a blood transfusion by Hawkgirl. The aliens' rocket lands, and Hawkman returns to the battle, gassing the invaders with argon, aging them all to death. The robots cease functioning as well, and Earth is saved.