Check out this CATIA V5 tip: http://www.ignitecast.com/p/aDql8F5IKm/
I created and uploaded this Ignitable to IgniteCAST.com to show you how create a section through an isometric view in CATIAV5. This tip is for intermediate CATIA V5 users using the Assembly Design workbench, so I hope you find it useful.
Steve