The helicopter are stopped in this case.
I didn't put  a kind "movement" on this yet.
Any way, thanks for your opinion.
 If you have any kind of hints that can improve this. I´ll thank.

Can't give useful comments about the colors, since I am a beginner in pixeling (-_-)

About the proportions though...Maybe the chopper can use longer blades :) (*or are they just folded? sorry if so )

Thanks Jalonso, i tried improve this colors. I think it looks a bit better now. 

I need more knowledges  about shadows and lights.

You may be unaware that we have different colored themes in PJ.
I use MoD's chocolate brown one and the AA on the shadow looks terrible.
I would add a BG or delete the AA : /

The copter itself is nice but the colors are a tiny bit weak. All is fixable : )