Several European states operate the same nuclear technical systems adapted to their operational needs. This may be particularly appropriate in functional airspace block (FAB) agreements (and subsequently in the context of the provision of Single European Sky Air Traffic Management Research). This approach extends international agreements beyond immediate operational requirements to provide broader support to the system. Several CSPs have started to develop agreements for the joint acquisition of common infrastructure; These agreements provide a model for the exchange of technical assistance in the event of an emergency. For example, it may be possible for system engineers to be sent by an ANSP to help those in a "failed" unit in another country. I have the honour to confirm receipt of your letter today, which reads as follows: for a list of airlines and services operating under Australian air agreements/arrangements, visit the International Airlines Timetable Overview page. Letters of agreement provide for the possibility of establishing mutual assistance in the context of contingencies. They allow for planning well before an incident occurs. Tests and exercises are used to determine whether or not States can implement the common approaches outlined in the unification letters. For more details on the legal issues related to it, see the article Legal aspects of the eventuality.
Letters of agreement define the policy of high-level cooperation between States under emergency conditions and may cover both operational and technical assistance. .