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.