What are departure Planning Information messages (DPI’s) and what are Advanced Tower messages?
DPI messages from a CDM Airport
The Departure Planning Information (DPI) messages are sent from the CDM airport to the NMOC (CFMU) to supply them with flight data related updates. The DPI messages contain accurate Estimated Take Off Times (ETOT), Target Take Off Times (TTOT), Taxi Times, aircraft type/registration and Standard Instrument Departures (SID) information. Subsequent DPI messages work as updates to previously sent information, containing progressively more accurate information.
These predictions or targets of the pushback and take-off events are received by the NMOC (CFMU) via DPI messages well in advance of the flight (Early DPI, Target DPI-t and Target DPI-s) and a latest update at the event of pushback (ATC DPI).
The NMOC (CFMU) processes the received DPI messages and if necessary, the CTOT is re-calculated.
With this mechanism of CTOT adaptation, based on Airport CDM derived TTOT, the aircraft operators will benefit as they receive a more flexible CTOT assignment compared to non-CDM airports.
DPI messages from Advanced Tower systems
What is an Advanced Tower system?
A tower with a system that has accurate information about the off-block event, an estimation of the taxi-out time (EXOT) resulting in an estimation of the take-off time.
The advanced tower system will be able to provide only one sub-type of DPI messages, i.e. the ATC-DPI (A-DPI), at the actual off-block event only.
These will be generated automatically and have to be part of the operational Tower procedures.
The provision of ATC DPI messages by an Advanced Tower System will only result in an early activation of a flight in ETFMS (Enhanced Tactical Flow Management System) at the NMOC.