End-End Enroute Trials

“Transfer Of Communications”

The TOC function allows the controller to uplink a CPDLC message instructing the pilot to either Contact (voice check-in) or Monitor (silent check-in) the next controller’s voice frequency. The system provides CPDLC eligibility indications to the sending and receiving controllers for each flight during the TOC process. The TOC process is triggered when a track handoff for an aircraft is accepted.

When the IC function is used, it replaces the pilot voice “check-in” procedure. The IC function requires the pilot to downlink the flight’s ATC assigned altitude. The ground system checks if the pilot downlinked assigned altitude matches the altitude displayed in that flight’s data block or, when applicable, a locally adapted altitude. The system provides indications to the sending and receiving controller during the IC process.

When used together, the TOC and IC functions make it possible to transfer an aircraft from one frequency to another silently. This “silent” check-in is only used for sector transfers within the same ARTCC.

CPDLC Transfer of Comminucations Messages: TOC uplink messages include an instruction to either Contact or Monitor, a facility name, facility type and a specified frequency.

·  uM169 CPDLC IN USE OR CPDLC NOT IN USE – Update concept doc -

·  uM117 CONTACT [icaounitname] [frequency]

o  Example: CONTACT INDIANAPOLIS CENTER 134.170 MHZ

·  uM120 MONITOR [icaounitname] [frequency]

·  uM135 CONFIRM ASSIGNED ALTITUDE

o  Example: MONITOR INDIANAPOLIS CENTER 134.170 MHZ, CONFIRM ASSIGNED ALTITUDE

·  Add confirm “assign altitude”

TOC CPDLC “Contact – Voice Check-In” Uplink Messages Requiring a Response

Step / TOC “Contact” Operating Method /
1 / The ATSU sends a TOC CPDLC Contact message requiring a response.
When the ATSU system sends a TOC CPDLC message, the controller may be notified.
2 / Upon aircraft system receipt of a TOC CPDLC Contact message requiring a response, the flight crew is notified.
3 / The flight crew may respond with DM2 STANDBY.
4 / Upon ATSU system receipt of a DM2 STANDBY, the controller may be notified.
5W / After the flight crew has determined that they can comply with a received TOC message requiring a W/U response the flight crew responds with a DM0 WILCO.
6 / The flight crew tunes into the flight deck radio tuning panel the assigned ATC Frequency from the Contact message, then makes voice contact with the receiving controller using standard contact procedures.

TOC “Monitor – Silent Check-In” CPDLC Uplink Messages Requiring a Response w/CAL Report

Step / TOC “Monitor” / Cal Report Operating Method /
1 / The ATSU sends a TOC CPDLC message requiring a response.
When the ATSU system sends a TOC CPDLC message, the controller may be notified.
2 / Upon aircraft system receipt of a TOC CPDLC message requiring a response, the flight crew is notified.
3 / The flight crew may respond with DM2 STANDBY.
4 / Upon ATSU system receipt of a DM2 STANDBY, the controller may be notified.
5W / After the flight crew has determined that they can comply with a received TOC message requiring a W/U response the flight crew responds with a DM0 WILCO.
5U / After the flight crew has determined that they cannot comply with a received message or do not understand the received message, the flight crew responds with a DM0 UNABLE.
6 / Upon ATSU system receipt of the flight crew TOC response:
·  when the response is other than UNABLE or NEGATIVE the controller may be notified, or
·  when the response is an UNABLE or NEGATIVE, the controller is notified.
7 / When the Uplink TOC CPDLC Monitor message contains a Confirm Assigned Altitude (CAL) report request, the flight crew will create the CAL Report and send report to the controller.
8 / Upon ATSU system receipt of the flight crew created CAL Report, the system may notify the controller.
9 / Upon receipt of a pilot Wilco response to the TOC message and the pilot created CAL report, the system will transfer CPDLC eligibility to the sector that acquired track control associated with the TOC., and remove the TOC-in-progress indications from the FDB. Lockheed> More detail than needed

US CPDLC TOC IC Use Case modes:

Transfer Of Communications “Automatic Mode”

In Automatic mode, the TOC is uplinked immediately upon acceptance of a handoff. The TOC will be in Automatic mode for a given transfer of track control if all of the following conditions are met:

  1. The sector initiating the handoff has CPDLC eligibility, the sector TOC mode setting is set to Automatic and the handoff was controller-initiated, or the sector TOC mode setting was overridden from Manual to Automatic in the handoff entry, or the sector TOC mode is Manual but the handoff is controller initiated to internal/external sectors and/or individual external facilities to which Automatic TOCs are enabled
  2. The handoff was accepted by a sector without a logic check override
  3. For an intra-facility handoff, the aircraft is predicted to enter an FAV in the sector that accepted the handoff
  4. For an inter-facility handoff, a frequency is received in the Transfer Accept (TA) message (when the setting to use frequencies received in the TA is ON) or a frequency is locally adapted for the sector that accepted the handoff
  5. There are no open uplink messages, with the exception of the CPDLC in use/not in use or current ATC unit messages, when the handoff is accepted by the next sector
  6. There are no abnormal uplink indicators in the FDB
  7. The aircraft is not in coast status at the sector with eligibility
  8. The aircraft is marked on-frequency at the sector initiating the handoff
  9. The aircraft does not have an IC-mismatch
  10. The aircraft does not have an Emergency CPDLC session

Manual Mode “Transfer Of Communications”

In Manual mode, a Held TOC is generated for CPDLC aircraft immediately upon transfer of track control and available for controller interaction. The Held TOC is not uplinked to the aircraft until the controller takes an explicit action to uplink it. The TOC will be in Manual mode and a Held TOC generated for a given transfer of track control if any of the following conditions are met:

  1. The sector TOC mode setting is Manual and in the handoff entry the controller does not inhibit the TOC or override the sector TOC mode to Automatic, and the receiving sector is not in the list of sectors to which auto TOCs are to be made
  2. A Held TOC exists for that aircraft at the sector with CPDLC eligibility
  3. The track is stolen by another sector
  4. The sector TOC mode setting is Automatic and any of the following conditions are met:
  5. The sector TOC mode is overridden from Automatic to Manual for a specific handoff in the handoff message
  6. There are open uplinks, with the exception of the CPDLC in use/not in use or current ATC unit messages, for an aircraft at the time the handoff is accepted
  7. There are abnormal uplink indicators in the FDB
  8. For intra-facility TOCs, the aircraft is not predicted to enter an FAV in the sector that received the handoff
  9. For an inter-facility handoff, no frequency is received in the Transfer Accept (TA) message and no frequency is locally adapted for the sector that accepted the handoff
  10. The handoff is accepted using a logic check override (e.g. stolen)
  11. The aircraft track is in Coast status at the time the handoff is accepted
  12. The aircraft is not marked on-frequency
  13. The aircraft has an IC-mismatch alert
  14. The track handoff was system initiated
  15. The sector TOC mode is overridden from Manual to Automatic and any of the following conditions are met:
  16. There are open uplinks for an aircraft at the time the handoff is accepted
  17. There are abnormal uplink indicators in the FDB
  18. The aircraft is not predicted to enter an FAV in the sector that received the handoff
  19. The handoff is stolen by a sector other than the one to which the handoff was addressed
  20. The aircraft track is in Coast status at the time the handoff is accepted
  21. Aircraft is not marked on-frequency
  22. The aircraft has an IC-mismatch alert
  23. The aircraft has an Emergency CPDLC session


End2End

1.  For flights that will participate in the Enroute CPDLC trials, airlines shall include in the Flight Plan appropriate Field 10 and Field 18 CPDLC remark codes for ERAM Processing. Other remarks should be included as necessary in Field 18. Any subsequent flight plans amendments should also include the CPDLC Flight Plan codes and remark codes. Manual connection only. (Andy F to fix)

2.  For intra facility Transfer of Communications (TOC) via CPDLC an Controller must have eligibility established with the aircraft prior to sending CPDLC messages to the aircraft. The FANS 1/A+ aircraft must be logged on to the Single Data Authority (SDA) via FANS AFN CM logon procedures. The Controller must have an aircraft data block indicating the aircraft is currently logged on and is CPDLC eligible.

3.  Depending on end system capability the transferring sector with TOC capability may have an Automatic or Manually Held TOC operation in place. The Controller on the receiving end may also require areas within the sector that may require Contact messages versus Monitor messages depending on the type of traffic being handled. Lockheed> TOC/IC is performed whenever a frequency change is required. Controller has the ability to override Automatic to a Manual TOC.

4.  When the Controller is ready to accomplish a TOC handoff, and the sector initiating the handoff has TOC CPDLC eligibility the Controller will send either a Contact or Monitor/CAL CPDLC message.

a.  Depending on the receiving sector CPDLC capability systems disconnect might occur once the TOC has occurred with the appropriate CPDLC flight crew response being received – Contact message to a non participating CPDLC facility.

b.  Lockheed> If a sector or site within the NAS does not have CPDLC eligibility, the eligibility token will be passed to the national Single Data Authority to hold.

c.  Upon of a Held state of CPDLC eligibility the Following CPDLC message will be sent to the aircraft: uM169 - CPDLC NOT IN USE, USE VOICE ATC PROCEDURES

d.  Handoff’s to outside the NAS – TBD – Negotiated NDA and switch to the new CDA upon the receipt of a Wilco on the TOC – Any open dialogs will be deleted. Disconnect or a Transfer will be the end result.

5.  The construction of the Contact CPDLC message (Voice Check-In) will be of the following content for a TOC being uplinked to the flight crew.

  1. uM117 CONTACT [unitname] [frequency]
  2. CONTACT INDIANAPOLISY CENTER 134.170
  3. When the aircraft receives a FANS CPDLC message it will alert the crew via an Aural and Visual means to indicate the aircraft has received a CPDLC message that is to be acted upon.
  4. The flight crew will select the message, review the Contact message independently, confer between them the message content, input the new ATC frequency into the radio tuning panel and ensure it is active, and respond to the CPDLC message appropriately, then call the receiving Controller via voice with their Call sign and Altitude confirmation. [GOLD Section 5 flight crew procedures for reviewing uplinked CPDLC messages].
  5. The sending Controller may receive an indication from the flight crew when they have responded to the uplinked TOC CPDLC message. In the event the flight crew responded with an UNABLE then the Controller will be notified. Appropriate TOC voice procedures should be enacted.

6.  The construction of a Monitor CPDLC message (Silent Check-In) with a Confirm Assigned ALTITUDE message and response from the flight crew will be as follows:

  1. uM120 [unitname] [frequency], concatenated with uM135 CONFIRM ASSIGNED ALTITUDE
  2. MONITOR INDIANAPOLIS CENTER 124.5, CONFIRM ASSIGNED ALTITUDE
  3. When the aircraft receives a FANS CPDLC message it will alert the crew via an Aural and Visual means to indicate the aircraft has received a CPDLC message that is to be acted upon.
  4. The flight crew will select the message, review the Monitor message independently, confer between them the message content, input the new ATC frequency into the radio tuning panel and ensure it is active, and respond to the CPDLC message appropriately, then
  5. The flight crew will create a response to the Confirm Assigned Altitude (DM38) by selecting the uplink response request, ensure the Assigned Altitude is properly displayed in the altitude report, verify with the flight crew member the accuracy of the altitude in the report, and then select send [GOLD Section 5 flight crew procedures for reviewing uplinked CPDLC messages].
  6. The system will receive two downlinks from the flight crew with a Monitor TOC with a CAL report. The Controller many or may not be notified depending on the response from the flight crew of the Monitor CPDLC message. Upon receipt of the Wilco Response to the Monitor message and the receipt of the Confirmed Altitude with automation checks for accuracy, the controller will be notified in the FDB the aircraft has been sent to the receiving sector.
  7. The system receiving sector, when CPDLC is eligible, will notify the Controller when an aircraft is checked on frequency using a Silent Check-in by a FDB notification.
  8. Optionally, when the receiving sector indicates to the controller the aircraft is silently checked-in, system automation may send to the aircraft a UM169 free text message indicating to the flight crew to “Verify Monitoring Frequency 124.5” (VMF).