To add to Alex's comment about the normal maps. Here's why it's the case on Dan's plane. One of the main spots I see it is the landing gear, the main surface being that somewhat triangular one that sits front and center on the nose gear. Well, it's not really a surprise, but here's how it's mapped. Just map it from the front, texturing will look the same, and we won't have to call Terminex to get all the ants off Dan's plane