Publisher Summary This chapter discusses the airworthiness requirements. The Basic Regulation establishes common requirements for the regulation of safety and environmental sustainability in civil aviation. It gives the European Commission powers to adopt detailed rules for the Regulation's implementation. When the Joint Aviation Requirements (JAR) requirements were first issued in the 1970s, several different standards for aircraft certification were in force in different countries. The Federal Aviation Regulations (FARs) issued by the Federal Aviation Administration (FAA) were adopted in the United States. The list of JARS and FARS directly or indirectly related to airworthiness certification includes: JAR 1/FAR 1. definitions and abbreviations, JAR 11. JAA regulatory and related procedures, FAR 11. general rulemaking procedure, JAR 21. certification procedures for aircraft and related products and parts, FAR 21. certification procedures for products and parts, and JAR 22. sailplanes and powered sailplanes.