I find the most common mistake I make (I also see others do too), is the presumption of what they think they see.
Lighting is the difference between a good profile and a really great profile.
Most of us here suffer from the insufficient reference syndrome.
Seeing as most of us don’t have an arsenal of WW2 military hardware parked in our back yards, we don’t have the “real deal” to work from.
Lighting isn’t constant and the way we see lighting in real life isn’t the same as we see it in a D2 drawing.
Sundin uses the same base techniques as the rest of us, but he has an eye for spotting the subtle changes that the rest of us miss.
He then exaggerates them slightly to “boost” his work, making it look more 3D that it probably would in real life. He is a clever artist for sure.
I don’t see a lot wrong with your I-16 here Gamary on the whole it looks very good, but its those little extra peaks of light and shade I see on Sundins work which set him above the rest of us.
I’ve blagged some arrows onto the areas I think have been “boosted”.
This is only my view on the matter so have a bag of salt ready

I include Sundins “magical texturing technique", which the rest of us can only dream about. < ---------- speaking for myself again