I'm not 100% sure of Brit Law but I don't
think Atlas Holdings/ AACS can terminate somebody for being union. I imagine a few of them are in unions already anyway. Your posting makes Atlas sound somewhat of an undesirable environment.
Is the job market not bouyant enough for the heavy metal pilots to tell them to take a hike anyway? You have my symapathies in the mean time. Do the guys in AACS know what they are into?