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“Push to Load” for En Route Data Comm

May 22, 2017
By: Stacy Honda, Marketing Manager

The FAA recently released a draft of Advisory Circular, (AC) 90-117 "Data Link Communications," which provides comprehensive guidance for aircraft eligibility and operational use of data link communications in the United States as well as other countries. The FAA sought comments to this draft (due on May 15, 2017), which we provided.

Aircraft Eligibility for Push to Load Requirement

The Push to Load requirement is outlined in Chapter 3: Aircraft Eligibility: "For en route National Airspace System (NAS) operations, the avionics system must have 'push to load' capability into the navigation system whenever a routing change is received for operations supported by B2 and Future Air Navigation System (FANS) 1/A (+) data link communication systems."

After careful consideration amongst our certification and flight department teams, we have taken the position that the 'push to load' provision is too onerous for the user-base and should be removed from the Aircraft Eligibility requirements for several reasons:

  1. Implementation is cost-prohibitive for the user-base
  2. The benefit of receiving a reroute clearance from Controller-Pilot Data Link Communications (CPDLC) versus a much less efficient voice clearance from ATC will be lost
  3. The Air Traffic Control (ATC) system enabling en route data link services is still evolving and has already required a new software update for FANS capable avionics that were originally thought to comply
  4. A large quantity of aircraft without a FANS solution today won't have an option for a significantly lower cost solution

Today, FANS equipped aircraft – even without push to load capability – are able to receive their departure clearance using DCL, and manually load it into the FMS. Significant efficiencies could be gained by using DCL during the enroute portion of the flight as well. Most pilots have experienced reroute clearances using voice that can produce multiple back-and-forth communications to get the new clearance correct. Understanding the waypoints / procedures of the new clearance and spelling them correctly can be a challenge, resulting in several minutes on the radio with ATC. After getting the clearance correct, the pilot enters the new route into the FMS. Most errors are attributed to pilots misunderstanding controllers and copying clearances incorrectly, not the manual entry of the new clearance into the FMS.

Receiving a new clearance while enroute via CPDLC, even without push to load, has significant benefits over voice communications. The pilot has everything needed in text format on the Control Display Unit (CDU) to copy the clearance down and enter it into the FMS. These benefits include:

  1. Reduced pilot errors in understanding clearance
  2. Reduced controller / pilot workload
  3. Higher adoption rate of Data Comm services, helping justify the Data Comm program
  4. Provides operators with additional justification for upgrading their fleet of aircraft, which could include aircraft without a FANS solution today (i.e. B717, A319, A320, CRJ, EMB, etc.)

UASC Position

We believe the U.S. Data Comm program will be a step forward, and will increase the safety and efficiency of aircraft and controller communications. However, a "push to load" mandate would deter operators from making the investment, resulting in a slower acceptance rate of the program.

Additional Information

For more information, be sure to read our blog post: AC 90-117: Why Your Input Is Important to Advancing the Efficiency & Safety of U.S. Airspace. There, you'll also be able to find a document with our comments, rationale, and recommendations for AC 90-117. Do you have any thoughts you'd like to share? If so, you can leave a comment to the blog post. Also, be sure to subscribe to the UA Blog to stay up-to-date with company news, industry topics, and regulatory trends – straight from our experts!

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