I am writing a seminar about military transport aircraft (fixed and rotary wings). I am stuck with categorising aircraft - classifying them as strategic, operational or tactical. I know that strategic airlift is an airlift over long distances (intercontinental, for example), and tactical is air transport to forward bases. I would like to know, if someone can help me with classification of operational air lifters. I have searched the topic on the Internet but so far I have not found any good material. If someone has knowledge about this topic or some useful links I would very much appreciate it.
Thank you for your help,