The following outbound messages can be sent by Dispatch for the flight plan
FPL - Outbound Flight Plan Message (FPL)
CHG - Outbound Modification Messages (CHG). A CHG message is transmitted when any change is made to the flight plan data contained in a previously transmitted FPL.
DLA - Outbound Delay Message (DLA). Delay Message (DLA) is sent to ATC advising them of the new requested departure time.
CNL - Outbound Cancellation (CNL) Message
SPL - Outbound Supplementary Flight Plan Message (SPL). This type of message will only be sent in reply to a request for supplementary flight plan data.
It’s important to note that you do not have to specify to Dispatch which messages to send. You can simply change or update your flight plan and Dispatch will automatically figure out what sequence of messages to send so that the flight plan is accurately updated within ATC systems.
For some regions of the world such as the United States and European countries, Dispatch is able to interpret the messages coming in from ATC. Dispatch supports the following incoming message types:
- ACK - Inbound Acknowledgement Message (ACK). ACK responses to FPL, CHG, DLA and CNL messages
- REJ - Inbound Rejection Message (REJ). REJ responses to FPL, CHG, DLA and CNL messages
- FLS - Flight plan suspension message sent by EUROCONTROL IFPS. These are sent if the flight plan gets suspended due to a route re-validation or the aircraft has not taken off within 30 minutes of its ETD
- DES - Flight plan de-suspension message sent by EUROCONTROL if a previously suspended flight plan becomes de-suspended
- SAM, SRM, and SLC - Slot allocation, revision and cancellation messages. Sent by EUROCONTROL if the flight plan is issued a ground delay (slot time / CTOT)
- RQS, RQP - Sent by ATC if they are re-requesting the flight plan (RQP) or requesting supplementary information about the flight (RQS)
If Dispatch receives a message that can not be automatically interpreted, the message is marked as UNK for the unknown. These might be acknowledgment or rejection messages sent by ATC in countries where Dispatch can not yet automatically interpret these. It might also be an important custom message from ATC to you about your flight plan.
If Dispatch receives an unknown message a letter icon is put on the ATC Data tab as well on the flight list to notify you of the unknown message.