Hey man this is looking superb overall, overall good balance of details, nice polyflow, good texturing. Really impressive once again, and just getting better.
My only suggestion is better control of normals, particularly around sharper edges. There are a few standout points of the model, but really its found throughout.
Quick example of what i mean below - what I'm seeing a lot on your model is A: Averaged normals over standard chamfers with no support loops, this leaves what should be 'flat' surfaces as having the appearance of curved normals.
I think an improvement would be to try using the B or C method, which is custom normals or 'fake chamfers' respectively - look at the wireframe image below and it should be self explanatory.
How you use them can depend on a few factors, so for example the silhouette is important, don't use 'fake chamfers'. I do recommend them for most things though, as it makes LODing super easy.
Here are some areas I found this really noticeable on your model:
This (oil?) tank - geometry says nice flat sides, normals (look at that horizon) say otherwise
Small ridge on the nose cone area - leaves a very wide transition to the surrounding bodywork:
I would really consider adding a support loop to help control the normals, like this bad drawing
Same with all the gearbox fins/ribs etc, all lacking normal control, so they are leaking into each other a bit, reducing their effect.
Close up of the same part - that tight of a radius there should be no blending between the two adjacent faces (blue lines supposed to be the control loops i'd add, poorly draw again)
Same with any 'sharp' corners of panel gaps, lacking control, making the normals act as if its much larger radii than they really are
Really easily fixed with a couple of extra loops
Anyway hope these illustrate the point - overall its still a really nice model, it doesn't detract too much. Something to keep in mind for next time
Great work
