Revision for “Ashtam Format” created on February 12, 2019 @ 00:45:36
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<strong>Instructions for the completion of the Ashtam Format</strong>
1.1 The ASHTAM provides information on the status of activity of a volcano when a change in its activity is, or is expected to be of operational significance. This information is provided using the volcano level of alert colour code given in 3.5 below.
1.2 In the event of a volcanic eruption producing ash cloud of operational significance, the ASHTAM also provides information on the location, extent and movement of the ash cloud and the air routes and flight levels affected.
1.3 Issuance of an ASHTAM giving information on a vol- canic eruption, in accordance with section 3 below, should not be delayed until complete information A) to K) is available but should be issued immediately following receipt of notification that an eruption has occurred or is expected to occur, or a change in the status of activity of a volcano of operational significance has occurred or is expected to occur, or an ash cloud is reported. In the case of an expected eruption, and hence no ash cloud evident at that time, items A) to E) should be completed and items F) to I) indicated as “not applicable”. Similarly, if a volcanic ash cloud is reported, e.g. by special air-report, but the source volcano is not known at that time, the ASHTAM should be issued initially with items A) to E) indicated as “unknown”, and items F) to K) completed, as necessary, based on the special air-report, pending receipt of further information. In other circumstances, if information for a specific field A) to K) is not available indicate “NIL”.
1.4 The maximum period of validity of ASHTAM is 24 hours. New ASHTAM must be issued whenever there is a change in the level of alert.
<strong>2. Abbreviated heading</strong>
2.1 Following the usual AFTN communications header, the abbreviated heading “TT AAiiii CCCC MMYYGGgg (BBB)” is included to facilitate the automatic processing of ASHTAM messages in computer data banks. The explanation of these symbols is:
3.1 Item A — Flight information region affected, plain- language equivalent of the location indicator given in the abbreviated heading, in this example “Auckland Oceanic FIR”.
3.2 Item B — Date and time (UTC) of first eruption.
3.3 Item C — Name of volcano, and number of volcano as
3.4 Item D — Latitude/Longitude of the volcano in whole degrees or radial and distance of volcano from NAVAID (as listed in the ICAO Manual on Volcanic Ash, Radioactive Material and Toxic Chemical Clouds (Doc 9691), Appendix H, and on the World Map of Volcanoes and Principal Aeronautical Features).
3.5 Item E — Colour code for level of alert indicating volcanic activity, including any previous level of alert colour code as follows:
3.7 Item G — Indicate forecast direction of movement of the ash cloud at selected levels based on advice from the responsible meteorological watch office and/or volcanic ash advisory centre.
3.8 Item H — Indicate air routes and portions of air routes and flight levels affected, or expected to become affected.
3.9 Item I — Indicate closure of airspace, air routes or portions of air routes, and availability of alternative routes.
3.10 Item J — Source of the information, e.g. “special air-report” or “vulcanological agency”, etc. The source of infor- mation should always be indicated, whether an eruption has actually occurred or ash cloud reported, or not.
3.11 Item K — Include in plain language any operationally significant information additional to the foregoing.
Source: ICAO Annex 15