Restrictions on Aligned Cross-Sections
An aligned cross section displays an area cross-sectional view that is unfolded around an axis. The system revolves all cutting planes of an offset cross section about the selected axis until they are oriented parallel to the screen (sheet).
Aligned cross sections create area-type cross sections. A full aligned cross section shows an aligned total cross section of a general, projection, or auxiliary view. You can make a detailed view from an aligned cross-sectional view.
The following restrictions apply to both aligned cross-sectional views and total aligned cross-sectional views:
You can align offset cross sections only.
The axis around which the cutting planes revolve must be parallel to the screen.
The axis must lie on all cutting planes.
The axis must be coaxial with all cylinders in the section.
If the view is to be general, orient the model so that the axis around which you are going to unfold is parallel to the screen.
The system creates aligned and unfolded cross-sectional views as area cross sections.
* 
Because a full aligned cross section is unfolded around an axis, it does not show the correct projection of the general view. Projecting it further would create a mismatch with the original general view. Hence, creating a projection view of a full aligned cross section is restricted.