Safety Oversight Manual Part A: The Establishment and Management of a State's Safety Oversight System. This manual outlines the duties and responsibilities of ICAO Contracting States with respect to aviation safety oversight. It is directed at high-level Government decision makers, as it highlights States' obligations as signatories to the Convention of International Civil Aviation (Chicago Convention) signed at Chicago on 7 December 1944, and provides information and guidance on the establishment of a State's safety oversight system which may be required to fulfill those obligations.