When trying to play custom maps there are times where the Rifleman/AH-64 will spawn as a bird.
This normally happens to me when I put down an individual unit.
It does NOT happen if I pick any other class like Marksman or in editor preview.
I've noticed that once you are dead and there is no respawn enabled the person will come back as a bird. I am not sure if this has a factor into why this is happening.