In my attempt to model a plane structure, I used a cylinder that I extruded to fit the shape. But on the final product, there are sharp edges at the point the extrusions end and start. Is there any way to fix it? 
I've tried applying Subdivision Surface modifiers, and it did not smooth out any of these. Also when turning on smooth shading, it ruins the cockpit part. Is there any other way to get rid of those apart from Smooth Shading?
