This is my tank for Combat Commander
I just picked up my copy today and had a flick through the rules. One thing I can't figure out is the EB-66 - it doesn't take up a slot and there doesn't seem to be any disadvantage in taking it on every mission. Other than the stress level of the pilot, or having the aircraft destroyed, is there any reason not to take it every time?
Stress will be the main reason it stays home. Sometimes I won't use it if I think I won't need it and want to leave it fresh for the next mission. I find it flies roughly half the missions.
Of course, you might not have it in your squadron at all. It's not a free pick for the squadron! It just doesn't count against the mission limit.