A design for a modification of, or repair to, an aircraft, aircraft engine, propeller or appliance is taken to have been approved for the purpose of these Regulations if the design is:
(a) approved by the national aviation authority of a recognised country; or
(b) for a design of a modification or repair that relates to an aircraft, aircraft engine or propeller designed in a recognised country--published or issued by the foreign type certificate holder of the aircraft, aircraft engine or propeller under a system approved by the national aviation authority of that country; or
(c) for a design of a modification or repair that relates to an appliance designed in a recognised country--published or issued by the manufacturer of the appliance under a system approved by the national aviation authority of that country; or
(d) accepted by CASA under an agreement (however described) regarding approvals of designs for modifications and repairs between:
(i) CASA and the national aviation authority of a Contracting State; or
(ii) Australia and a Contracting State.