Part 21
Certification Procedure for Products and Parts
Part 23
Airworthiness Standards
Part 27
Airworthiness Standards (Rotorcraft)
Part 33
Airworthiness Standards (Engines)
Part 35
Airworthiness Standards (Propellers)
Part 39
Airworthiness Directives
Part 43
Maintenance (How)
Part 47
Aircraft Registration
Part 65
Certification [(Other than flight crew) Who]
Part 91
General Operating and Flight Rules (When)
Part 119
Certification (Air carriers and Commercial Operators)
Part 125
Certification and Operation of Large Aircrafts
Part 135
Operating Requirements (Commuter and On-Demand)