Which organization issues TSO?

The General Authority of Civil Aviation (GACA) is the correct organization that issues Type Safety Orders (TSO). GACA is the regulatory authority for civil aviation in Saudi Arabia, responsible for establishing policies and standards that ensure the safety of civil aviation operations in the country, including the issuance of TSOs. These orders provide guidance and specifications for aviation products, processes, and services operating under their jurisdiction, aligning with national and international safety standards.

While the Federal Aviation Administration (FAA) does issue similar directives in the United States and the International Civil Aviation Organization (ICAO) sets international safety standards and regulations, GACA specifically issues TSOs pertinent to Saudi Arabia's aviation context. The Aviation Safety Network (ASN) does not issue regulations or orders but rather serves as a database and resource for aviation safety information. Thus, the specificity of GACA's role in Saudi Arabia makes it the correct answer.