i know in the usa there are airlines like Mesa, Replublic, PSA, Skywest runs under US Airways and they share there $$$$ and sign a contract i tink that would be cool to do 
You can do that. By obtaining other company’s shares and getting dividends.
ok thanks but i am not familiar with the stock market can the airline give you shares or do they have to take the risk of someone esle takeing the shares
they are being traded on a free market. well, not really a free market but everyone is free to participate
I think what you mean is franchising. In real life large airlines outsource part of their operations to smaller airlines for efficiency. These airlines are integrated into the mainlines booking system and also branded as mainline flights. In airlinesim this only partly possible, as you have no real code-share options. Still you could found a "regional" subsidary that operates your local flights. Or you could talk to a player who runs a smaller airline and make a deal for an exclusive interlining to support your hub. While branding won’t matter to airlinesim passengers you could still offer these companies a logo similar to your, so that there is a homogenous impression on the airport boards…