The nose of the fuselage is flat on top. Making it a bit more rounded improves the airplaneās appearance.
Improve the curvature of the top front portion of the fuselage:
  Click and Ctrl+click to select the three ridgeline
               edges in front of the cockpit, and the ridgeline edge immediately
               behind it.
               
  Move these edges up vertically
               a bit, to make the fuselage more rounded.

Front view
Increase the curvature at the top of the engine cowl:
  (Vertex) sub-object level.
            
  Click and Ctrl+click to select the three vertices
               along the top of the engine cowl.
  Move these vertices up a
               bit, as well.

Front view
  (Vertex) to turn it off
               and exit the Vertex sub-object level.
            
  zoom out and press F4 to turn off Edged Faces.
            
 Edit panel, turn on  
  (NURMS) once again.
               Now the fuselage is convincingly rounded.

  (NURMS).