Oh, if you want smoother nurbs surfaces;

Hit ctrl-A and set the TESSELATION per nurb-surface;
from default (1.5) to 3, 4, 6, 8 or more if needed. But the fuselage of your airplane could get away with 4 or 6 i guess.

If your modelspace has edgy nurbs-curves;
Hit 2 (Medium default) or 3 (max default) on the keyboard.
This setting and its parameters under (Ctrl-A) NURBS does not have anything to do with the rendered image or calculation.

Tesselation-settings improves the quality and complexity of the nurbs-curves and surfaces.