Question: Looking for movie featuring Dragons vs. Navy (or Army, but the trailer featured battleship trying to shoot the dragons down).

Trailer also showed a dogfight between helicopters and dragons, capping (on the trailer) with a dragon setting a Blackhawk's blades on fire.

Answer: 
Sounds similar to [Dragon Wars : D-War](https://en.wikipedia.org/wiki/D-War), although I haven't found a specific trailer (of which there are quite a few) with a Blackhawk's blades on fire. Plenty of dragons destroying helicopters in other ways though. Here is a [short trailer](http://www.imdb.com/video/screenplay/vi3466789145), and here is a [longer trailer](https://www.youtube.com/watch?v=YnQXvQ1R4gg). Some of the dialogue in the longer trailer is Korean, but the movie itself is mostly in English.

![Dragon-vs-copter](https://i.stack.imgur.com/Gk9s1.png)
MainStay Productions released a trailer on YouTube last year, about a movie project they are working on with BluFire Studios, ostensibly called Crimson Skies.
The premise is that a volcanic island erupts, releasing thousands of dragons from millenia-long slumber, that attack a small fleet of Navy vessels.

I checked on both MainStay and BluFire's websites, neither of which make any mention of the project, which makes me think that the trailer may simply be a "pitch demo" to try and find a studio willing to underwrite it. There is no other mention of the movie, other than the video, that I can find. 

Of course, this may also be just another elaborate YouTube hoax.