Appendix 4

ASHTAM FORMAT

INSTRUCTIONS FOR THE COMPLETION OF THE ASHTAM FORMAT

1.         General

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 volcanic eruption, in accordance with section 3 below, shall not be delayed until complete information A to K is available but shall 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 shall 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 shall 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 a day. New ASHTAM shall be issued whenever there is a change in the level of alert.

2.         Abbreviated heading

2.1       Following the usual ‘Aeronautical fixed – telecommunications network (AFTN)’ communications header, the abbreviated heading ‘TT AAiiii CCCC MMYYGGgg (BBB)’ shall be included to facilitate the automatic processing of ASHTAM messages in computer databanks. The explanation of these symbols is:

TT =                                          data designator for ASHTAM = VA;

AA =                                         geographical designator for States, e.g. NZ = New Zealand;

iiii =                                          ASHTAM serial number in a four-figure group;

CCCC =                        four-letter location indicator of the flight information region concerned;

MMYYGGgg =          date/time of report, whereby:

MM =                                       month, e.g. January = 01, December = 12;

YY =                                          day of the month;

GGgg =                       time in hours (GG) and minutes (gg) UTC;

(BBB) =                       Optional group for correction to an ASHTAM message previously

                                                               disseminated with the same serial number = COR.

Brackets in (BBB) shall be used to indicate that this group is optional.

3.         Content of ASHTAM

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 listed in ICAO Doc 9691 Manual on Volcanic Ash, Radioactive Material and Toxic Chemical Clouds, Appendix H, and on the World Map of Volcanoes and Principal Aeronautical Features.

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 Doc 9691 Manual on Volcanic Ash, Radioactive Material and Toxic Chemical Clouds, 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:

The colour code for the level of alert indicating the status of activity of the volcano and any change from a previous status of activity shall be provided to the area control centre by the responsible vulcanological agency in the Member State concerned, e.g. ‘RED ALERT FOLLOWING YELLOW’ OR ‘GREEN ALERT FOLLOWING ORANGE’.

3.6       Item F – If volcanic ash cloud of operational significance is reported, the horizontal extent and base/top of the ash cloud shall be indicated using latitude/longitude (in whole degrees) and altitudes in thousands of metres (feet) and/or radial and distance from source volcano. Information initially may be based only on special air-report, but subsequent information may be more detailed based on advice from the responsible meteorological watch office and/or volcanic ash advisory centre.

3.7       Item G – Forecast direction of movement of the ash cloud at selected levels shall be indicated based on advice from the responsible meteorological watch office and/or volcanic ash advisory centre.

3.8       Item H – Air routes and portions of air routes and flight levels affected, or expected to become affected, shall be indicated.

3.9       Item I – Closure of airspace, air routes or portions of air routes, and availability of alternative routes, shall be indicated.

3.10    Item J – Source of the information, e.g. ‘special air-report’ or ‘vulcanological agency’, etc. The source of information shall always be indicated, whether an eruption has actually occurred or ash cloud reported, or not.

3.11    Item K – Any operationally significant information, additional to the foregoing, shall be included in plain language.