Out Of Office Hours Automation

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Hellenic Slot Coordination Authority

Out of Office Hours Automatic Message Processing


The Hellenic Slot Coordination Authority would like to announce the initialization of the Automatic Message Processing procedure that is now active during out of office hours.


The Rules and Guidelines of the procedure are as follows and shall apply to Commercial and General/Business aviation requests:

  • Automatic Message Processing will be active everyday from 13:30 UTC (16:30 LT Summer Time) until 05:30 UTC (08:30 LT Summer Time) the following working day. Weekends and Bank Holidays are included.
  • Requests that will be processed are:
    • Single date only
    • Within the same or next day (horizon extends on weekends or bank holidays)



It is strongly advised that requests that concern such operations are sent in SCR (Commercial requests)/GCR (GA/BA requrests) messages separately from any other request for the convenience of the sender as well as the flow of the message processing.


Any lines in the message that fail to meet processing conditions will not be processed. A reply will be produced by the system where any lines that were not processed will be returned with action code W along with the relevant brief reason for not processing.


Requests that contain SSIM syntax errors, slot database errors or airports that are not in the airport database of HSCA will be automatically rejected in all cases during the operational period of this system, even for requests that concern operations that are not in the same or next working day. This system limitation cannot be avoided. A relevant header will be present in the reply message. In the case of a missing airport the sender should use airport codes:

  • ZZI – for Intra-Schengen country airport, or,
  • ZZE – for Extra-Schengen country airport


In addition, the sender should include the airport code in question in the SI part of the request to be added to the database and corrected in the relevant field of the database. The coordinator shall inform the sender when this corrective action occurs.


General Rules

  • The Minimum accepted ground time is 20 minutes.
  • All requests must be in linked format unless otherwise entitled.
  • Requests must be single date only and within the same or next day, this horizon extends on weekends and Bank Holidays.
  • Requests that are in past time or within the next 30 minutes will be considered retrospective and will not be processed.
  • Long ground time requests will be processed for the convenience of the operators and will be replied to with action code K (if there no constraint breaches). The request will be normally subject to final approval by airport operator. An exception is the airport of SKG where the procedure has changed and LGT approval procedures have been eliminated.
  • Mixed carrier codes are prohibited in the messages unless legally able to transfer slots between them, relevant to Article 8a “Slot Mobility” of EEC regulation 95/93 as amended by EEC 793/2004.
  • Slot swaps and slot transfers will not be accepted by the system. A reply will not be produced and the message will remain in the inbox to be examined by the coordinator during office hours.
  • General and Business Aviation changes of registration will be considered slot transfers for the purpose of this document and will be subject to penalties of misuse.


The coordinators will closely monitor usage of the Automatic Message Processing system and all users must adhere to the general rules. Should misusing the system or exploiting the rules of usage be discovered, the coordinators reserve the right to proceed with corrective actions in their discretion.


We would like to thank everyone involved in the testing of this system for HSCA.


Please report any error or query to This email address is being protected from spambots. You need JavaScript enabled to view it.


Thank you for your cooperation and we wish for a fruitful S18 season.


The above can be downloaded as a document in *.pdf format from here.