By changing the Fuselage design policy from monotonic to loop, the first cross-section is enforced to be at the same location as the final section at 1.0x design length. The final section is also forced to exactly match the design of the first section. This ensures that the component surface follows a user-defined loop and closes. Typical uses of this feature are to design “hollow” nacelles, rocket nozzles, tubes/pipes, or turbojet/fan engine station internals. This tutorial demonstrates how to apply the loop design policy to a Fuselage component and some of the important aspects of modeling this way.