Theres a RUvsUK server thas has helis :)

There's currently a mod that the developer's have made. It's called "OH:D Vehicle Overhaul"
It's got about a dozen or so tanks and several attack helicopters. After you've subscirbed and started a game with the "OH:D Overhaul" gameode you can play with helis (You need to be an admin to spawn them online, but in single player press the "Home" key or type "/zeus" into the chat to enter the spawn menu (The /zeus command hasn't been working for me so if it doesn't work for you just stick with the Home key at the top right of your keyboard).

Thanks friend, I didn't have this information when I installed the mod. But for some reason, I can't fly armed aircraft, I can only fly those with crew. I can't use any missiles or machine guns from helicopters available in the game. If you have any information about this, I'd appreciate it.