Can harpy eagle kill golden eagle in a midair fight?

Yes, it could happen - but it is not likely to happen since the Harpy Eagle (Harpia harpyja) lives in Central and South America while the American Bald Eagle, the National Symbol of the United States of America, is found from Alaska and Canada to Northern Mexico; the natural ranges of the two species do not overlap. The Harpy Eagle is the largest eagle in the Americas, with the females having a wingspan up to 8.2 feet (2.5 meters) and weigh up to 20 lbs (9 kilos). In comparison, the female American Bald Eagle (Haliaeetus leucocephalus) attains a weight of between 12 and 13 lbs and a wingspan of up to 7 feet. The Harpy Eagle's talons are also longer than the talons of the brown bear (Ursus arctos); the American Bald eagle's talons are only about half as long as the Harpy's.

The females of both species are generally larger than the males, but the size differential between the two species is still proportionate for the males.