So you bought a piu-piu-helicopter? I find it useless. It can only fight cultist mansion vehicles (and even not all of them). But is it really worth to fight them at all? Cultist vehicles activate only when you are close to a mansion and after that fall into sleep for a while. So you don't even have to "clear your way" for ground troops. I am not sure even about do pilots even gain experience from air battles...
Do you also find it frustrating, that on special mission screen there is info about allowed armor, but no info about what craft can be used? Before every such mission I have to "test" it using OSPREY to see allowed crafts. Text about allowed equipment is also vague. Mostly you can understand that, but not always. I was almost certain, that you can take only concealed weapons on the final Syndicate mission. Luckily I wasn't playing on Ironman...