It is already unchecked in my setup. I puposely set all my bombers to no formations some time ago, simply because I dont fly them that often, there are too many issues associated with formations that I dont want to have to deal with if I decide to fly one, and it avoids the issue of perkies being wasted on something I dont care to use anyway (having a formation).
Again. I didnt try to takeoff in one. I just pulled the bird up on my screen. It told me I didnt have enough perks to fly it. I did. It was already setup as a single bird, not a formation. Simple enough.