I think it's main shortfall is the lighting. If you look, the sun is behind the aircraft, yet the light is concentrated on the left hand side, with relatively little falling on the right.

You must take this into account when you take the original shot, so it doesn't look out of place in the real picture.

Hope this helps.

Very nicely cut out, cool shot. As said, a bit too much light on the lower left side, but still 

Sorry, but I think the position of the aircraft takes something away from the rest of the picture. Other than that, the way it's composed, and the lighting is beautiful 

Maybe just work on having a more realistic pitch for the 737