Theres only a few things to separate this drawing from perfection. 1.The lines on the propeller-section are too visible.
2. The shadow under the plane is somehow weird particularly under the wings
3. The ground in the front of the "wheelcase" (?) is slightly bent
4. This "lever-thing" coming from the top is somehow different rendered.
5. The landscape far behind is too "even" or not in balance.
All the rest is perfect! I suppose you have also noticed these very minor things, so this comment is probably not a big deal to you. Maybe I am wrong here, but thats what Id do if the drawing was made by me (unluckily its not)
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