Description:CS-23 Amendment 3. Effective: 20 July 2012. The following is a list of paragraphs affected by this amendment. Book 1. Subpart D. • CS 23.851. Amended (NPA 2011-14). Subpart E. • CS 23.1197. Amended (NPA 2011-14). Book 2. AMC - Subpart D. • AMC 23.851(c). Amended (NPA 2011-14).