Part 21 of CASR deals with the certification and airworthiness requirements for aircraft and aircraft parts. It includes rules relating to Type Certificates, Type Acceptance Certificates, Supplemental Type Certificates, Production Certificates, Certificates of Airworthiness and export airworthiness approvals. It also covers the approval of aircraft engines, propellers, and certain materials and parts. It calls up the airworthiness certification standards mentioned in Parts 22-35:

22 - Sailplanes
23 - Small Aeroplanes
25 - Transport Category Aeroplanes
26 - Primary/Intermediate category aeroplanes
27 - Rotorcraft
29 - Rotorcraft (Transport Category)
31 - Manned free balloons
32 - Engines for Very Light Aeroplanes
33 - Aircraft Engines
35 - Aircraft propellers.