Hey Gamary, nice clean profile, and by clean I mean nice and sharp.
There are a few things you could do concerning the definition of shapes and separation of parts.
Your shadow areas tend to flatten your shapes a bit, especially under the wing. You need to remember that, except for weird lighting conditions, shadows are stronger and sharper closer to the object that is casting them.
Also, with the shadow ares under the wing, the nacelle tends to almost disappear. Here is a quick quick quick example I made-

I didn't address the sharp to fuzzy shadow here. One other thing I did was to pull the wing tip out more. To show an object is protruding, getting closer to the viewer, you can darken it. Also color can be used to do this, richer color to show closer object.
On the wheel, the gear strut almost blends in with the wheel. Another example-

I also rounded the shadow some where it cuts across the tire.
These are pretty simple corrections, but you can get as complicated or stay simple with how much you do.
Just remember to define the shapes. We all start with flat drawings, the next step is to pull the shapes off the page.
What you've got is very nice work, just a little more definition and it will be 100%