I know that wild turkeys can fly enough to roost high in trees at night. However, Carlson and Co. would not have dropped wild turkeys. They were no doubt factory-farmed overbred turkeys, whose feathers may be clipped to keep them on the farm and under control.
I understand that they are bred and selected for more breast meat than nature intended. I have read that as a result, they must be artifically inseminated as they cannot manage the task the natural way, as they overbalance and fall over.
Of course, knowing the competence of the WKRP crew, Herb Tarlek probably got a deal on frozen turkeys.
Disclaimer: I am not a turkey farmer, nor do I play one on TV.