Snap, indeed. Chickens can fly (just not very far). While there was never a time when chickens filled the skies, their ancestors were a bit more adept than current breeds.

Did chicken ancestors fly?

Game birds, such as pheasants and grouse, and the closest ancestor to the chicken (i.e. the jungle fowl) can actually fly, albeit for a very short distance. They do what is called “burst flight”, meaning they exert most of their energy by taking-off almost vertically to flee predators as fast as possible.

Could chickens fly before they were domesticated?

This selective breeding and lack of evolution for survival, as well as their predecessors, are the reasons as to why chickens cannot fly. (1) However, in the case that they would need to, their wing structure would allow them to fly a short distance, far enough to reach safety in a tree's lower branches.