As outlined in Annex 11 of the Chicago Convention, the ICAO Council approved for the first time, on June 27, 1984, guidelines for contingency measures to be applied in the event of interruption of air traffic services and related support services, pursuant to Assembly Resolution A23-12, after study by the Air Navigation Commission and consultations with States and interested international organizations as requested in that resolution.

Subsequently, the guidelines were amended and expanded in light of the experience gained from the application of contingency measures in various parts of the world and in different circumstances.

The objective of the guidelines is to help ensure the safe and orderly flow of international air traffic in the event of disruption to air traffic services and related support services and to ensure that the major global air routes of the air transport network remain available in such circumstances.

The guidelines have been prepared taking into account that the circumstances preceding and accompanying events leading to the disruption of services to international civil aviation vary widely and that contingency measures, including access to designated aerodromes for humanitarian reasons, taken to deal with specific events and circumstances must be adapted to those circumstances. The guidelines set out the responsibilities of States and ICAO for the organization of contingency plans and the measures to be taken into account in the preparation, implementation and termination of contingency plans.