Aviation legislation - MAXIMUM TAKE-OFF MASS:
Aircraft companies intending to manufacture a new design must have approval under Chapter A8-1 of BCAR or JAR-21 (Certification Procedures for Aircraft and Related Products and Parts). Usually, manufacturing companies have additional approvals in other categories, such as: Overhauler A8-3; Test House A8-6 Design A8-8; etc.
Suppliers to a manufacturer, can be in one of two categories. If they have A8-2 or JAR-21 approval they are responsible for their own quality control. If they do not have approval, then the manufacturer of the aircraft, to whom they are supplying equipment or parts, is responsible for maintaining standards.
The publication JAR-21, mentioned above, controls the procedural requirements for the issue and changes to Type Certificates, it also controls the issue of ‘standard Certificates of Airworthiness and Export Airworthiness Approvals, (C of A for Export).' JAR-21 also lays down the procedures for approval of ‘certain parts and appliances'.
The approval of organisations requiring issue of the above certificates and approvals is also prescribed by JAR-21, as are the ‘rules governing the holders of any certificate or approval'.