As I already admitted, illustrations of people or creatures were never my strong point, so now I wanted to implement something I feel more comfortable with. I took another sheet of paper, and started to sketch abstract Learjets from different angles. When I finally found a good perspective, I drew the plane again, but this time with more details. I am not sure yet, but I think that it will not be a big deal to recreate this sketch in Illustrator. - At least I hope so.
Left: The first sketch of the plane from this specific angle. Right: The second sketch with more details and more precise alignment of all elements. This plane is fictitious and does not exist in reality.