I think it looks extremely good and real!

Looks nice from gibts also pictures from another view? back front and other side? =D and vllt inside =)

Real life->Minecraft: little deviation.
Why the thrower?

As cannon

@Jangar I think your creation is beautiful! only there is no helicopter in the world with a cannon! Since cannons would have crashed the plane, because of the recoil, have you ever seen a tank fighter on TV or real shooting? The vehicles get knocked back by the recoil, imagine a recoil like that in the air!
If, then it can be a MK (machine gun), since the armament of helicopters are often against ground targets and not against air targets, a MK is superfluous, and a MG (machine gun) much more effective! Since this has a higher rate of fire, of course, today's helicopters still have rocket drums and others. These you can rebuild without mods but difficult. I find your helicopter great! Only he is not suitable for me, because I build in a different scale.
Also, please tell me which helicopter you used as a model.

Ehm... First *WoW* I just built on it xD Well "cannon" was maybe the wrong word but there are not so many ways to build a MG in Minecraft

It looks really good
I would like to build it and can you please upload more pictures