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- airspace activities in the vicinity of airports;
- airspace activities affecting more than one FIR;
- outages of navigation aids affecting serving several airports and/or FIR;
- establishment of ATS airspace serving more than one airport;
- obstacles in the vicinity of several airports
- etc.
The reason is primarily related to how NOTAM are currently selected for inclusion in Pre-flight Information Bulletins (PIB), based on the item A ( which may contain one airport code or up to seven FIR codecodes). It has to be assured that the NOTAM appear correctly in the relevant en-route and airport PIB and that duplication in PIB (e.g. in the FIR) are avoided. Depending on the number of affected airports and FIR, NOTAM format limitations such as the limitation of Item A item A content limitations (maximum 7 FIR or 1 airport), NOTAM series allocation or other national requirements, different options exist to assure correct PIB inclusion. The The NOTAM for the en-route and airport part of the PIB may also be combined, provided NOTAM rules are respected. This is often done to reduce the number of NOTAM issued.
The most frequent practical solution is to identify one airport and its associated FIR by one NOTAM (with scope AE) and issue any additional airport (or FIR) NOTAM separately. An alternative is to completely separate FIR from airport NOTAM and issuing When more than one FIR is affected, the typical solution is to issue one NOTAM for the FIR or FIR(s) all the affected FIRs and one NOTAM for each affected airport/heliport. This practice is explained in the OPADD version 4.1, item 2.3.9.3.
Airport PIB is served by Q-line qualifier scope A, the airport affected is indicated in Item A. En-route PIB is served by Q-line qualifier scope E or W (depending on the event), the FIR(s) affected is indicated in Item A. In the case of NOTAM combining scope AE or AW, the FIR can be derived from the Q-line FIR or more frequently by database association of the airport indicated in Item A.
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The Event association with airports and/or FIR allows for explicitly identifying the additional aerodromes and/or FIR to which the Event is associated. Alsoaffected by the Event Also, an Event can have several NOTAM associated.
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