Inside the FMS
Inside the FMS
Why is the FAA Banning General Aviation Operators from En-Route CPDLC?
Several years ago, the FAA released its plan to allow datalink communications over the domestic United States. It was similar to the concept that EASA is implementing in Europe; however, instead of using a new higher speed network (ATN), the FAA chose to use the existing Future Air Navigation System (FANS 1/A) technology.
The FAA’s program named Data Comm is short for Datalink Communications. The plan is for it to be rolled out in 5 phases with each phase incrementally adding more functionality and providing more capability for ATC to communicate digitally with the crew. The first phase was the use of Data Comm for Departure Clearances Procedures (DCL), completed in December, 2016. It was an improvement over the already existing Pre-Departure Clearance (PDC) function and allowed for clearances to be pushed directly from ATC to the aircraft, inserted directly into the flight management system, and revised if necessary.
Phase two of the Data Comm initiative is the offering of limited enroute communication services (much the same as what Canada currently does in many regions). This will allow for Initial Check-ins, Altimeter Settings, Speed Assignments, Altitude Restrictions, and several others to be sent to the flight crew (See Figure 1).
|Figure 1. Data Comm Roadmap|
Phase two is being launched initially with Kansas City and Indianapolis ARTCC and will then be migrated to the remaining ARTCCs by 2021. L3Harris is the prime contractor for the FAA’s Next Gen Data Comm program. They participate in an industry organization known as the Data Comm Integration Team (DCIT).
Recently, L3Harris released a letter to the DCIT stating they have had some technical difficulties impacting the acceptability of service. As a result, the FAA and L3Harris are temporarily limiting all Business and General Aviation FANS avionics platforms from the En-Route CPDLC trials during the implementation phase. The intent is to bring these avionics platforms back online once the implementation is complete. During trials the FAA is using a small sampling of avionics versions found in several air transport aircraft that they have tested and found acceptable. For the complete list on the L3Harris website, click here. L3Harris will begin to assess the performance of Business and General Aviation aircraft systems beginning in Q4 2019.
|L3Harris Recommended Avionics Versions (All)|
In the interim, it is important to understand:
• There is no impact to airspace access in the U.S.
• PDC and DCL remain unaffected and can be used as they were previously
• CPDLC En-Route services are temporarily suspended and will be handled by voice
• Flight plans should not be filed with FANSER in field 18 of the flight plan
• Honeywell, along with other avionics manufacturers and communication service providers are working with the FAA/L3Harris to improve the system performance.