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The safety assessment conducted to determine the ITP separation minimum was undertaken by ICAO for global application.

Within the scope of this safety assessment, it is necessary to distinguish between assessments undertaken by States for the purposes of implementation at the local level and those undertaken by ICAO from a global perspective. An assessment undertaken for global purposes does not always contain the information required to address specific local implementation requirements.

For example, because safety considerations are largely determined by the local operational environment, into which an international Standard is to be integrated, a full safety assessment should take into consideration the local operational environment. As such, airspace planners need to complement the ICAO assessment with a regional or local implementation-focussed assessment. It should be noted that a local implementation assessment may not necessarily require a regional assessment but may be initiated by an ANSP on a case-by-case basis. Figure 3-1 depicts the difference in the types of assessments.

As described in 2.6 of the PANS-ATM, a safety assessment shall be carried out in respect of proposals for significant airspace reorganizations, for significant changes in the provision of air traffic service (ATS) procedures applicable to an airspace or an aerodrome, and for the introduction of new equipment, systems or facilities. Since ITP will introduce a reduced separation minimum to be applied within an airspace, prior to the implementation, each State shall conduct its own safety assessments and analyse its local safety cases taking into account many risks which were outlined in the safety, performance and interoperability requirements in DO-312 and ED-159.

Note.— Although ICAO undertook a global assessment, States should note that ICAO's assessment is based on a number of assumed characteristics related to either the airspace environment or aircraft performance; therefore there are possibilities that ICAO was not able to assess all of the factors that might affect safety during State or Local implementations. These characteristics may not necessarily be the same as those relevant to any particular regional, State or local implementation.