The competent authorities (Assoclearance) send to the airports information on the operational slots requested by the airlines for the operation of flights covered by the airport, through messages that use a coded format and, therefore, recognizable in every part automatic. These messages are called “clearance” (SCR). Therefore, the other clearances are only codified messages that inform the airport staff of all the actions related to a managed flight.

Flight scheduling data as well as manually can also be automatically inserted into the Time Table thus ensuring both greater reliability of information and almost irrelevant update times. The automatically acquired Clearance can be consulted and eventually modified before being officially inserted in the Time Table.

“Flight Programming” allows to acquire SCR also from files prepared by operators and stored in their working directories. The use of operator files for the acquisition of SCR is extremely useful at the beginning of the season to allow the automatic insertion of historical SCRs. The latter in fact do not follow the SITATEXT online channel but are sent by Assoclearance off-line and with non-standard formats. In this case the operator is called to format a real SCR file as communicated in electronic files typically in Excel format. The SCRs acquired automatically are, however, positioned at the end of the tree related to the season to which they belong. In case of attempted acquisition of SCR incorrect from the operator files, a message appears indicating the missed acquisition. For them, a red SCR node is not created on the tree, as it happens for those automatically acquired by SITATEXT, but the operator is reminded to modify the original file and then try again the acquisition. Once acquired, the SCRs can be updated in the relevant Time Table. The system updates all the SCRs that have not yet been updated to the selected SCR. Downstream of the update, the SCRs can no longer be changed or updated. In case of need of modification it will be necessary to operate directly in the Time Table or to create new modification SCRs.

The updating function also ensures that a Time Table automatically switches from “ACTIVE” to “IN CHANGE”. In fact, an active Time Table on which the SCRs are actualized continues to operate according to its previous contents until a qualified operator requests a new activation. The change in status is made to indicate that the Time Table has undergone changes that have not yet been activated.

An SCR may contain several actions and each action may include a departing flight, an incoming flight or both in the case of two flights.