JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21)

Table G-1: RVR reduction for EVS equipped aircraft (continued)

RVR normally re-

quired

RVR for approach

utilizing EVS

RVR normally required

RVR for approach uti-

lizing EVS

1500

1000

3900

2600

1600

1100

4000

2600

1700

1100

4100

2700

1800

1200

4200

2800

1900

1300

4300

2800

2000

1300

4400

2900

2100

1400

4500

3000

2200

1500

4600

3000

2300

1500

4700

3100

2400

1600

4800

3200

2500

1700

4900

3200

2600

1700

5000

3300

Rule
Visibility credit for EVS is not applied on Jeppesen Standard charts.

COMPARISON OF AOM CONCEPTS

The table below compares AOM concepts which are defined as being “similar” to ICAO Doc 9365
according to Jeppesen AOM rules. The table is intended to make operators aware of the devia-
tions from Doc 9365 to provide guidance to the pilots.

AERODROME OPERATING MINIMUMS - JEPPESEN

1377

JEPPESEN AERODROME OPERATING MINIMA

NOTE 1: “Std” label is used for AOM based purely on ICAO Doc 9365 rules. “Std/State” indicates
that there are only a small number of differences to the ICAO Doc 9365 as indicated in the table
above. “TERPS” indicates that the minimums are based on TERPS. Operators have to analyze
the differences to provide guidance to the pilots.
NOTE 2: Some countries publish a minimum RVR for CAT III only, not for CAT IIIB and/or CAT
IIIA. For those countries Jeppesen will not differentiate between CAT IIIB and CAT IIIA. Pilots
have to compare the charted RVR against the approved company minimum.
NOTE 3: On some CAT III operations a DH is required. Because the DH depends on several fac-
tors which might be operator specific, the operator has to provide guidance to the pilots. A specific
DH is only charted if it is published by the State for the applicable CAT III procedure.
NOTE 4: An LPV might be designed as CAT I or as APV approach procedure. Because of the
differences in CAT I and APV minimums, the procedure header in the minimums box will be
shown as “LPV CAT I” for European charts. Operators have to provide guidance to the pilots
whether the LPV procedures can be flown or not.
NOTE 5: For PANS-OPS and TERPS circling procedures the circling speeds and circling areas
are different. Operators have to analyze the differences to provide guidance to the pilots.
NOTE 6: SA CAT I and SA CAT II procedures are mainly published in the United States. Opera-
tors need a specific approval and have to provide guidance to the pilots.
NOTE 7: LTS CAT I and OTS CAT II are mainly published in the European Region. Operators
need a specific approval and have to provide guidance to the pilots. Currently LTS CAT I mini-
mums are only displayed on tailored charts on customer request. OTS CAT II minimums are only
displayed if such a procedure is published in the AIP. EASA plans to remove LTS CAT I and OTS
CAT II from the regulation in Q4/2020 and will provide new guidance for SA CAT I and SA CAT II
procedures.
NOTE 8: Jeppesen charts will provide the lowest possible minimums for the airport. The normal
take-off minimums box will not differentiate between the runways, which may have different
runway lighting, unless required because of State-provided minimums. Pilots are reminded that
for all take-off minimums below RVR 550m/VIS 800m low visibility procedures might be required.
Pilots are also reminded that for take-offs in RVR below 400m a specific approval might be
required. Operators which still have an approval according to a CAR-OPS version which is based
on earlier EASA AMC/GM (CAT C and D aircraft have different minimums) have to analyze the
differences to provide guidance to the pilots.
NOTE 9: The minimums are charted as RVR unless a State provides VIS or CMV values as mini-
mums for the approach procedure. Depending on the available lighting an ATC reported visibility
can be converted into a CMV to compare it against a charted RVR/CMV. Whenever a VIS value is
charted in the minimums box, an ATC reported visibility must not be converted. An ATC reported
RVR can be compared against a charted RVR/CMV.
NOTE 10: It is the operator/pilot responsibility to verify that low visibility procedures (LVP) are in
force if they are required. Some States do not use the term “low visibility procedures” or they do

AERODROME OPERATING MINIMUMS - JEPPESEN

1380

JEPPESEN AERODROME OPERATING MINIMA

not publish the procedures within the AIP. If CAT II/III operations are in progress, then low visibil-
ity procedures are in force.
NOTE 11: Operators need a specific approval for low visibility take-off operations and have to pro-
vide guidance to the pilots. “Low Visibility Take-off” is only shown in the take-off boxes based on
EASA AIR OPS or Indian CAR rules.
NOTE 12: Operators may reduce the required RVR if using an Enhanced Vision System if they
are approved for doing this. Jeppesen does not chart EVS RVR minimums.
NOTE 13: The comparison is only valid for CAT C and D aircraft because the harmonized TERPS
Table 3-3-1 excludes CAT A and B aircraft.
NOTE 14: The initial version published by EASA (EU-OPS 1) contained the old JAR-OPS take-off
minimums, where the lowest RVR for CAT C and D is different (125m vs 150m). The rules from
this publication were applied by several State Authorities but not updated with the latest changes
on EASA AIR OPS rules. Therefore the take-off minimums are different to the take-off minimums
provided in ICAO Doc 9365.

AERODROME OPERATING MINIMUMS - JEPPESEN

1381

JEPPESEN AERODROME OPERATING MINIMA

Extracted from Doc 10037 - Global Operational Data Link (GOLD) Manual – First Edition

GENERAL

These pages provide guidance and information concerning data link aspects of aeronautical activ-
ity and is intended to facilitate the uniform application of Standards and Recommended Practices
contained in Annex 2 — Rules of the Air and in Annex 11 — Air Traffic Services, the provisions in
the Procedures for Air Navigation Services — Air Traffic Management (PANS-ATM, Doc 4444)
and, when necessary, the Regional Supplementary Procedures (Doc 7030).

FLIGHT CREW PROCEDURES

OVERVIEW

General

4.1.1.1 The operator may be required to obtain a necessary approval by the State of the Opera-
tor or State of Registry to use CPDLC and ADS-C services. This chapter provides guidance on
procedures for the flight crew in airspace where data link services are available.
4.1.1.2 These procedures are intended to assist operators in the development of:

a. operating procedures and associated documentation; and
b. appropriate training programs.

4.1.1.3 Flight crews should be knowledgeable in operating manuals for use of the data link
system specific to the aircraft type.
4.1.1.4 Flight crews should be knowledgeable in data link operations.

Operational Differences between Voice Communications and CPDLC

4.1.2.1  Development, testing, and operational experience have highlighted fundamental differ-
ences between voice communications and CPDLC. These differences need to be considered
when developing or approving flight crew procedures involving the use of CPDLC.
4.1.2.2  For example, when using voice communications, each flight crew member hears an
incoming or outgoing ATS transmission. With voice, the natural ability for each flight crew member
to understand incoming and outgoing transmissions for their own aircraft has provided a certain
level of situational awareness among the flight crew. With CPDLC, flight crew procedures need to
ensure that the flight crew has an equivalent level of situational awareness associated with under-
standing the content and intent of a message in the same way.
4.1.2.3  Each flight crew member (e.g. pilot flying and pilot monitoring) should individually review
each CPDLC uplink message prior to responding to and/or executing any clearance, and individu-
ally review each CPDLC downlink message prior to transmission. Reading a message individually
is a key element to ensuring that each flight crew member does not infer any preconceived intent
different from what is intended or appropriate. Reading the message aloud would bias the other
flight crew member and could lead to the error of 'reading' what was read aloud as opposed to
what was actually displayed.

4.1

4.1.1

4.1.2

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1383

DATA LINK OPERATIONS

4.1.2.4  Some uplink messages, such as complex or conditional clearances, require special
attention to prevent the flight crew from responding to a clearance with RSPD-1 WILCO, but not
complying with that clearance. To minimize errors, when responding to a clearance with RSPD-1
WILCO, each flight crew member should read the uplink message individually (silently) before ini-
tiating a discussion about whether and how to act on the message.
4.1.2.5  In a similar manner, each flight crew member should individually review CPDLC down-
link messages before the message is sent. Having one flight crew member (e.g. the pilot monitor-
ing) input the message and having a different flight crew member (pilot flying) review the message
before it is sent provides an adequate level of situational awareness comparable to or better than
voice communication.
4.1.2.6  If an operator uses augmented crews, the flight crew carrying out the ‘handover’ briefing
should thoroughly brief the ‘changeover’ flight crew or flight crew member on the status of ADS-C
and CPDLC connections and messages, including a review of any pertinent uplink and downlink
CPDLC messages (e.g. conditional clearances).
4.1.2.7  The flight crew should coordinate uplink and downlink messages using the appropriate
flight deck displays. Unless otherwise authorized, the flight crew should not use printer-based
information to verify CPDLC messages as printers are not usually intended for this specific pur-
pose.
NOTE: For aircraft that have CPDLC message printing capabilities, there are constraints associ-
ated with the use of the flight deck printer. Printers may not produce an exact copy of the dis-
played clearance with the required reliability, and should not be used as the primary display for
CPDLC. However, in some cases, printed copies may assist the flight crew with clearances and
other information that are displayed on more than one page, conditional clearances and crew
handover briefings.

When to use Voice and when to use CPDLC

4.1.3.1 When operating within airspace beyond the range of DCPC VHF voice communication,
CPDLC is available and local ATC procedures do not state otherwise, the flight crew should nor-
mally choose CPDLC as the means of communication. The flight crew would use voice as an
alternative means of communication (e.g. VHF, HF or SATVOICE direct or via a radio operator).
However, in any case, the flight crew will determine the appropriate communication medium to
use at any given time.
4.1.3.2 In airspace where both DCPC VHF voice and CPDLC communication services are provi-
ded, and local ATC procedures do not state otherwise, the flight crew will determine the communi-
cation medium to use at any given time.
NOTE: ICAO Doc 4444, paragraph 8.3.2, requires that DCPC be established prior to the provision
of ATS surveillance services, unless special circumstances, such as emergencies, dictate other-
wise. This does not prevent the use of CPDLC for ATC communications, voice being immediately
available for intervention and to address non-routine and time critical situations.

4.1.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1384

DATA LINK OPERATIONS

4.1.3.3  To minimize pilot head down time and potential distractions during critical phases of
flight, the flight crew should use voice for ATC communications when operating below 10000ft
AGL.
4.1.3.4  While the CPDLC message set, as defined in Appendix A, generally provides message
elements for common ATC communications, the flight crew may determine voice to be a more
appropriate means depending on the circumstances (e.g. some types of non-routine communica-
tions).
NOTE: Refer to paragraph 4.6 for guidelines on use of voice and data communications in emer-
gency and non-routine situations.
4.1.3.5  During an emergency, the flight crew would normally revert to voice communications.
However, the flight crew may use CPDLC for emergency communications if it is either more expe-
dient or if voice contact cannot be established. Refer to paragraph 4.6.2 for guidelines on use.
NOTE: For ATN B1 aircraft, emergency message elements are not supported. See Appendix A,
paragraph A.4.9, for a list of emergency message elements.
4.1.3.6  Except as provided in paragraph 4.6.1.2, the flight crew should respond to a CPDLC
message via CPDLC, and should respond to a voice message via voice.
NOTE: This will lessen the opportunity for messages to get lost, discarded or unanswered
between the ATS unit and the flight crew and cause unintended consequences.
4.1.3.7  If the intent of an uplink message is uncertain, the flight crew should respond to the
uplink message with RSPD-2 UNABLE and obtain clarification using voice.
NOTE: For FANS 1/A aircraft, some uplink messages do not have a DM 1 UNABLE response. On
these aircraft, the flight crew should respond with DM 3 ROGER and then obtain clarification via
voice.
4.1.3.8  Regardless of whether CPDLC is being used, the flight crew should continuously monitor
VHF/HF/UHF guard frequency. In addition, the flight crew should continuously maintain a listening
or SELCAL watch on the specified backup or secondary frequency (frequencies).

LOGON

General

4.2.1.1 A CPDLC connection requires a successfully completed logon before the ATS unit can
establish a CPDLC connection with the aircraft.
4.2.1.2 Prior to initiating the logon, the flight crew should verify the following:

a. the aircraft identification provided when initiating the logon exactly matches the aircraft iden-

tification (Item 7) of the filed flight plan;

b. the flight plan contains the correct aircraft registration in Item 18 prefixed by REG/;

c. the flight plan contains the correct aircraft address in Item 18 prefixed by CODE/, when

required;

4.2

4.2.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1385

DATA LINK OPERATIONS

d. the flight plan contains the correct departure and destination aerodromes in Items 13 and 16,

when required; and

e. the aircraft registration provided when initiating the logon exactly matches the aircraft plac-

ard, when the flight crew manually enters the aircraft registration.

NOTE 1: If a logon request has been initiated with incorrect aircraft identification and aircraft reg-
istration, the logon process will fail. The flight crew will need to correct the information and reiniti-
ate the logon request.
NOTE 2: For operators who do not provide an actual copy of the filed flight plan to the flight crew,
the required information will be available to the flight crew in equivalent flight planning documents.
4.2.1.3 If any of the items in paragraph 4.2.1.2 do not match, the flight crew will need to contact
AOC or ATC, as appropriate, to resolve the discrepancy.
NOTE 1: In accordance with ICAO Doc 4444. the aircraft identification is either the:

a. ICAO designator for the aircraft operating agency followed by the flight identification; or
b. aircraft registration.

NOTE 2: The aircraft registration entered into the aircraft system can include a hyphen (-), even
though the aircraft registration in the flight plan message cannot include a hyphen.
NOTE 3: The ATSU correlates the data sent in a logon request message with flight plan data. If
the data does not match, the ATSU will reject the logon request.
NOTE 4: For operators who do not provide an actual copy of the filed flight plan to the flight crew,
items found in error may be corrected by AOC, provided that the flight crew is notified of the
changes.
4.2.1.4  The flight crew should then manually initiate a logon using the logon address.
NOTE 1: Often the logon address is the same as the 4-letter FIR location identifier but in some
airspace a different CPDLC logon address is used. Refer to Appendix B.
NOTE 2: Some aircraft implement FANS 1/A and ATN B1 capabilities as separate systems and
do not comply with ED154A/DO305A. For these aircraft, the flight crew will have to select the
appropriate system (FANS 1/A or ATN B1) to initiate the logon.
4.2.1.5  If there are no indications that the logon procedure was unsuccessful, the flight crew can
assume that the system is functioning normally and that they will receive a CPDLC connection
prior to entry into the next ATS unit’s airspace.
4.2.1.6  If an indication that the logon procedure was unsuccessful is received, the flight crew
should reconfirm that the logon information is correct per paragraphs 4.2.1.2 and 4.2.1.4 and
reinitiate a logon.
NOTE: If the logon information is correct and the logon process fails, see paragraph 4.7.3 for
more information.
4.2.1.7  Each time a CPDLC connection is established, the flight crew should ensure the identi-
fier displayed on the aircraft system matches the logon address for the controlling authority.

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1386

DATA LINK OPERATIONS

4.2.1.8 In the event of an unexpected CPDLC disconnect, the flight crew may attempt to reiniti-
ate a logon to resume data link operations.
4.2.1.9 The flight crew may receive a CPDLC free text message from the ATS unit or a flight
deck indication regarding the use of the message latency monitor on FANS 1/A+ aircraft. When
this message is received, the flight crew should respond as described in Table 4-1 and in accord-
ance with procedures for the specific aircraft type.
NOTE 1: Procedures associated with the message latency monitor are applicable only in the
European Region and are described in Appendix B, B.2.3.2.
NOTE 2: FANS 1/A aircraft do not support the message latency monitor.

Table 4-1. Messages and indications regarding use of message latency monitor

Instruction to switch message latency monitor off

ATS unit TXTU-1 CONFIRM MAX UPLINK DELAY VALUE IS NOT SET
Flight
crew

FANS 1/A+ aircraft

Message latency monitor not available

The flight crew should:

a. confirm that the message latency

monitor is off (or not set), and

b. respond to the uplink [free text] mes-

sage with DM 3 ROGER.

The flight crew should respond to the
CPDLC (free text) message with RSPD-4
ROGER.

Instruction to set the maximum uplink delay value

ATS unit SYSU-6 LATENCY TIME VALUE (latency value)

where the (latency value) is an integer value, e.g., 40

Flight
crew

FANS 1/A+ aircraft

Message latency monitor not available

The flight crew should:

a. set the value; and
b. respond to the uplink message with

DM 3 ROGER.

The flight crew should respond to the up-
link (free text) message with RSPD-4
ROGER and append the TXTD-2 TIMER
NOT AVAILABLE.

Indication of delayed CPDLC uplink message (some FANS 1/A+ aircraft only)

ATS unit/
aircraft
system

(any CPDLC uplink message displayed with indication of delayed message)

Flight
crew

Some FANS 1/A+ aircraft only

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1387

DATA LINK OPERATIONS

Table 4-1. Messages and indications regarding use of message latency monitor (contin-

ued)

The flight crew should:

a. revert to voice communications to notify the ATS unit of the delayed message re-

ceived and to request clarification of the intent of the CPDLC message (para-
graph 4.7.2.2 refers); and

b. respond, appropriately, to close the message per the instructions of the control-

ler.

When to log on initially for data link services

4.2.2.1  When operating outside data link airspace, the flight crew should initiate a logon 10 to 25
minutes prior to entry into airspace where data link services are provided.
NOTE: When departing an aerodrome close to or within such airspace, this may require the logon
to be initiated prior to departure.
4.2.2.2  Where a data link service is only provided in upper airspace and where local procedures
do not dictate otherwise, the flight crew should log on to that ATS unit in whose airspace a data
link service will first be used.
4.2.2.3  When failure of a data link connection is detected, the flight crew should terminate the
connection and then initiate a new logon with the current ATS unit.

Automatic transfer of CPDLC and ADS-C services between ATS units

4.2.3.1  Under normal circumstances, the current and next ATS units automatically transfer
CPDLC and ADS-C services. The transfer is seamless to the flight crew.
NOTE: The flight crew should not need to reinitiate a logon.
4.2.3.2  The flight crew should promptly respond to CPDLC uplinks to minimize the risk of an
open CPDLC uplink message when transferring to the next ATS unit.
NOTE: If a flight is transferred to a new ATS unit with an open CPDLC message, the message
status will change to ABORTED. If the flight crew has not yet received a response from the con-
troller, the downlink request will also display the ABORTED status.
4.2.3.3  Prior to the point at which the current ATS unit will transfer CPDLC and/or ADS-C serv-
ices, the flight crew may receive a response to close any open CPDLC messages.
4.2.3.4  When entering the next ATS unit’s airspace, the flight crew should confirm the success-
ful transfer from the current ATS unit to the next ATS unit by observing the change in the active
ATS unit indication provided by the aircraft system.
4.2.3.5  When required by local procedures, the flight crew should send RTED-5 POSITION
REPORT (position report). Alternatively, the flight crew may be required to respond to a CPDLC
message exchange initiated by the ATS unit.

4.2.2

4.2.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1388

DATA LINK OPERATIONS

NOTE: Since FANS 1/A aircraft do not report that the downstream ATS unit has become the
CDA, the only way to confirm that it has taken place is for the ATS unit to receive a CPDLC mes-
sage from the aircraft (refer to Appendix B).

Transfer voice communications with the CPDLC connection transfer

4.2.4.1 Prior to crossing the boundary, the active ATS unit may initiate transfer of voice commu-
nications with the CPDLC connection transfer using any of the message elements containing
CONTACT or MONITOR.
4.2.4.2 A CONTACT or MONITOR message instructs the flight crew to change to the specified
frequency and may include a position or time for when to change to the new frequency.

a. When a MONITOR message is received, the flight crew should change to the specified fre-

quency upon receipt of the instruction or at the specified time or position. The flight crew
should not establish voice contact on the frequency.

b. When a CONTACT message is received, the flight crew should change to the specified fre-

quency upon receipt of the instruction or at the specified time or position, and establish voice
contact on the frequency.

NOTE 1: Some States do not require HF SELCAL checks. If, following a MONITOR instruction, a
SELCAL check is specifically required by operator procedures, this will usually be accommodated
on the allocated frequency.
NOTE 2: If the next ATS unit provides CPDLC services, the flight crew should not expect that
CPDLC will be terminated or suspended once voice contact is established per receipt of a CON-
TACT message, unless otherwise advised.
NOTE 3: CONTACT/MONITOR messages may specify a SATVOICE number.
4.2.4.3 If the ATS unit assigns a single HF frequency, the flight crew should select a secondary
frequency from the same ‘family’.
NOTE: In areas of poor radio coverage, the controller may append COMU-4 SECONDARY FRE-
QUENCY (frequency) to specify a secondary frequency.

Exiting CPDLC and ADS-C service areas

4.2.5.1  Approximately 15 minutes after exiting CPDLC and/or ADS-C service areas, the flight
crew should ensure there are no active CPDLC or ADS-C connections. Ensuring that connections
are not active eliminates the possibility of inadvertent or inappropriate use of the connections.
4.2.5.2  The flight crew should consult the current ATS unit prior to the manual termination of any
ADS contract, even if it is suspected to be unnecessary or that its termination has failed.
4.2.5.3  In the event that the connection termination has failed, the flight crew should contact the
ATS unit via voice or any other appropriate means.
NOTE: ADS contracts are managed (e.g. established and terminated) by ATS units.

4.2.4

4.2.5

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1389

DATA LINK OPERATIONS

CPDLC – UPLINK MESSAGES

General

4.3.1.1 When a CPDLC uplink is received, each flight crew member (e.g. pilot flying and pilot
monitoring) should read the message from the flight deck displays individually to ensure situa-
tional awareness is maintained. Once the message has been individually read, the flight crew
should then discuss whether to respond to the message with RSPD-1 WILCO or RSPD-4
ROGER, as appropriate, or RSPD-2 UNABLE.
4.3.1.2 When processing a multi-element uplink message, the flight crew should ensure that the
entire uplink has been read and understood in the correct sequence prior to responding.
NOTE: A CPDLC multi-element message is one that contains multiple clearances and/or instruc-
tions. The display may only show part of a CPDLC multi-element message and require flight crew
interaction to see the entire message.
Example:

Controller

LVLU-6 CLIMB TO FL350
LVLU-23 REPORT LEAVING FL330
LVLU-24 REPORT MAINTAINING FL350

Flight crew

RSPD-1 WILCO

4.3.1.3  If multiple clearances are received in a single message, the flight crew should only
respond with RSPD-1 WILCO if all the clearances in the entire message can be complied with.
4.3.1.4  If the flight crew cannot comply with any portion of a multi-element message, the flight
crew should respond to the entire message with RSPD-2 UNABLE.
NOTE: The flight crew can only provide a single response to the entire multi-element uplink mes-
sage. The flight crew cannot respond to individual elements of a multi-element message and
should not execute any clearance contained in the message.
4.3.1.5  When an uplink responded to with RSPD-1 WILCO or RSPD-4 ROGER, the flight crew
should take appropriate action to comply with the clearance or instruction.
NOTE: Although a RSPD-1 WILCO or RSPD-4 ROGER response technically closes the uplink
message, in some cases, other responses may follow to provide additional information, as
requested, to operationally close the message.
4.3.1.6  The flight crew should respond to an uplink message with the appropriate response(s),
as provided in Appendix A.
NOTE 1: The flight crew may need to perform some action before a subsequent CPDLC message
can be displayed.
NOTE 2: For ATN-B1 systems, if the ground system does not receive a response within 120 sec-
onds from the time the uplink message was sent, the ATS unit will send an ERROR message for
display to the flight crew and both the aircraft and ground system close the dialogue.

4.3

4.3.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1390

DATA LINK OPERATIONS

4.3.1.7 When a message is received containing only TXTU-1 free text element, or a TXTU-1
free text element combined with elements that do not require a response, the flight crew should
respond to the message with RSPD-4 ROGER before responding to any query that may be con-
tained in the free text message element.

Flight crew response times for CPDLC uplink messages

4.3.2.1 System performance requirements have been established to support reduced separation
standards. Specific latency times have been allocated to the technical performance, and flight
crew and controller response times. Regional/State monitoring agencies analyze actual perform-
ance to ensure the technical and operational components of the system meet required standards.
For example, to support RCP 240 operations, the flight crew is expected to be able to respond to
a CPDLC uplink message within one minute.
4.3.2.2 For an ATN-B1 aircraft, the flight crew should respond to a CPDLC uplink message
within 100 seconds to prevent the CPDLC uplink message from automatically timing out.
NOTE: ATN-B1 aircraft use a CPDLC message response timer, which is set at 100 seconds upon
receipt of the CPDLC uplink message. If the flight crew has not sent a response within this time:

a. the flight crew is no longer provided with any response prompts for the message;
b. the aircraft sends an ERROR message for display to the controller; and

c. the aircraft and ground systems close the dialogue.

4.3.2.3  When a CPDLC uplink message automatically times out, the flight crew should contact
ATC by voice.
4.3.2.4  The flight crew should respond to CPDLC messages as soon as practical after they are
received. For most messages, the flight crew will have adequate time to read and respond within
one minute. However, the flight crew should not be pressured to respond without taking adequate
time to fully understand the CPDLC message and to satisfy other higher priority operational
demands. If additional time is needed, the flight crew should send a RSPD-3 STANDBY
response.
NOTE: For ATN B1 aircraft systems, if the flight crew does not send an operational response
within 100 seconds after the RSPD-3 STANDBY was sent, the CPDLC uplink message will time
out (refer to paragraph 4.3.2.3).
4.3.2.5  If a RSPD-3 STANDBY response has been sent, the flight crew should provide a subse-
quent closure response to the CPDLC message.
NOTE 1: In the case of a RSPD-3 STANDBY response, the uplink message remains open until
the flight crew responds with a RSPD-1 WILCO or RSPD-2 UNABLE. If the closure response is
not received within a reasonable period of time, the controller is expected to query the flight crew.
NOTE 2: Transmission times for messages may vary for a number of reasons including the type
of transmission media, network loading, or the criteria for transitioning from one media to another
(e.g. VHF/Satcom). Operational response times may vary depending on workload and complexity
of the instruction or clearance.

4.3.2

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1391

DATA LINK OPERATIONS

Conditional clearances

4.3.3.1 Conditional clearances require special attention by the flight crew, particularly for a non-
native English speaking flight crew. A conditional clearance is an ATC clearance given to an air-
craft with certain conditions or restrictions such as changing a flight level based on a time or
place. Conditional clearances add to the operational efficiency of the airspace. Conditional clear-
ances, however, have been associated with a large number of operational errors. Following
guidelines provided in paragraphs 4.1.2 and 4.3.1, such as a) each flight crew member individu-
ally reading the uplinked clearances and b) conducting briefings with augmented crews, should
aid in reducing errors.
4.3.3.2 The flight crew should correctly respond to conditional clearances containing “AT” or
“BY”, taking into account the intended meaning and any automation features provided by the air-
craft systems. Table 4-2 clarifies the intended meaning for conditional clearance message ele-
ments. (Refer also to Appendix A.)

Table 4-2. Conditional clearance clarification of vertical clearances

Message Intent

Message element

Instruction that at the specified time a climb to
the specified level or vertical range is to com-
mence and once reached the specified level is
to be maintained.
NOTE 1: Instruction that, NOT BEFORE the
specified time, a climb to the specified level is
to commence and, once reached, the specified
level is to be maintained.
NOTE 2: This message element would be pre-
ceded with LVLU-5 MAINTAIN (level), to pre-
vent the premature execution of the instruction.

LVLU-7 AT TIME (time) CLIMB TO (level)

Instruction that at the specified position a climb
to the specified level or vertical range is to com-
mence and once reached the specified level is
to be maintained.
NOTE 1: Instruction that, AFTER PASSING the
specified position, a climb to the specified level
is to commence and, once reached, the speci-
fied level is to be maintained.
NOTE 2: This message element would be pre-
ceded with LVLU-5 MAINTAIN (level), to pre-
vent the premature execution of the instruction.

LVLU-8 AT (position) CLIMB TO (level)

4.3.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1392

DATA LINK OPERATIONS

Table 4-2. Conditional clearance clarification of vertical clearances (continued)

Message Intent

Message element

Instruction that at a specified time a descent to
a specified level or vertical range is to com-
mence and once reached the specified level is
to be maintained.
NOTE 1: Instruction that, NOT BEFORE the
specified time, a descent to the specified level
is to commence and, once reached, the speci-
fied level is to be maintained.
NOTE 2: This message element would be pre-
ceded with LVLU-5 MAINTAIN (level), to pre-
vent the premature execution of the instruction.

LVLU-10 AT TIME (time) DESCEND TO (level)

Instruction that at the specified position a de-
scent to the specified level or vertical range is
to commence and once reached the specified
level is to be maintained.
NOTE 1: Instruction that, AFTER PASSING the
specified position, a descent to the specified
level is to commence and, once reached, the
specified level is to be maintained.
NOTE 2: This message element would be pre-
ceded with LVLU-5 MAINTAIN (level), to pre-
vent the premature execution of the instruction.

LVLU-11 AT (position) DESCEND TO (level)

Instruction that a climb is to commence at a
rate such that the specified level is reached at
or before the specified position. When this mes-
sage element is not concatenated with another
vertical clearance, the level specified is the as-
signed level which is to be maintained.

LVLU-12 CLIMB TO REACH (level single) BE-
FORE TIME (time)

Instruction that a climb is to commence at a
rate such that the specified level is reached be-
fore passing the specified position.

LVLU-13 CLIMB TO REACH (level single) BE-
FORE PASSING (position)

Instruction that a descent is to commence at a
rate such that the specified level is reached be-
fore the specified time.

LVLU-14 DESCEND TO REACH (level single)
BEFORE TIME (time)

Instruction that a descent is to commence at a
rate such that the specified level is reached at
or before the specified position.

LVLU-15 DESCEND TO REACH (level single)
BEFORE PASSING (position)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1393

DATA LINK OPERATIONS

“EXPECT” uplink messages

4.3.4.1 “EXPECT” uplink messages are typically received in response to a flight crew request,
and, in some cases, when procedurally required.
4.3.4.2 When receiving an EXPECT uplink message, the flight crew should respond with
RSPD-4 ROGER, meaning that the message was received and understood.
NOTE 1: The flight crew should NOT comply with an EXPECT message as if it was a clearance.
NOTE 2: The FANS 1/A CPDLC message set contains EXPECT uplink message elements that
the controller should NOT use because of potential misinterpretation in the event of a total com-
munication failure. See Appendix A and Appendix B, B.4.1.3 for specific message elements that
are not supported.

Uplinks messages containing FMS-loadable data

4.3.5.1  CPDLC allows aircraft systems to be capable of loading route clearance information
from CPDLC messages directly into an FMS. The flight crew can use this capability to minimize
the potential for data entry errors when executing clearances involving loadable data. It also ena-
bles advanced ATS supported by data link, such as a re-route or a tailored arrival, which other-
wise may not be possible via voice.
NOTE: Not all aircraft have the capability to load information from CPDLC message directly into
the FMS.
4.3.5.2  If a clearance is received that can be automatically loaded into the FMS, the flight crew
should load the clearance into the FMS and review it before responding with RSPD-1 WILCO.
4.3.5.3  The flight crew should verify that the route modification in the FMS is consistent with the
CPDLC route clearance. A discontinuity in a CPDLC route clearance is not necessarily a reason
to respond to the clearance with RSPD-2 UNABLE, as these can be appropriate in some circum-
stances.
4.3.5.4  The flight crew should respond to the clearance with RSPD-2 UNABLE when:

a. the FMS indicates that it cannot load the clearance (e.g. partial clearance loaded or unable

to load); or
NOTE: The FMS checks the clearance to ensure it is correctly formatted and compatible with
the FMS navigation database.

b. the FMS indicates any inconsistencies or discontinuities with the route modification that are

not addressed by AIP (or other appropriate publication) or cannot be resolved by the flight
crew.

4.3.5.5 The flight crew should use CPDLC or voice to clarify any clearance that was responded
to with RSPD-2 UNABLE due to any loading failures, route discontinuities or inconsistencies.
4.3.5.6 If the clearance loads successfully and is acceptable, the flight crew may execute an
FMS route modification and respond to the clearance with RSPD-1 WILCO.
NOTE: The flight crew will ensure the route in the FMC matches the ATC clearance.

4.3.4

4.3.5

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1394

DATA LINK OPERATIONS

CPDLC – Downlink Messages

General

4.4.1.1  Downlink messages can only be sent to the ATS unit that holds the active CPDLC con-
nection. To provide situational awareness, procedures should ensure that each flight crew
member has read each downlink message before it is sent.
4.4.1.2  When the aircraft has an active CPDLC connection with an ATS unit, the flight crew
should downlink a clearance request only if the flight is in that ATS unit’s airspace.
4.4.1.3  The flight crew should use standard downlink message elements to compose and send
clearance requests, CPDLC position reports, and other requested reports. Additional qualifying
standard message elements, such as SUPD-1 DUE TO (specified reason downlink) or DUE TO
WEATHER, should also be used as needed.
NOTE: The use of standard message elements will minimize the risk of input errors, misunder-
standings, and confusion, and facilitate use by a non-native English speaking flight crew. The use
of standard message elements allows the aircraft and ground systems to automatically process
the information in the messages that are exchanged. For example, the flight crew can automati-
cally load clearance information into the FMS and review the clearance, the ground system can
automatically update flight plan data for route conformance monitoring, and both aircraft and
ground systems can associate responses to messages.
4.4.1.4  To avoid potential ambiguity, the flight crew should avoid sending multiple clearance
requests in a single downlink message. For example, the flight crew should send separate down-
link messages for LVLD-2 REQUEST CLIMB TO [level] and RTED-1 REQUEST DIRECT TO
[position] unless there is an operational need to combine them in a single message (i.e., the flight
crew does not want to climb unless they can reroute).
4.4.1.5  When a closure response to an open CPDLC downlink message is not received within a
reasonable time period, the flight crew should:

a. for a FANS 1/A aircraft, send a query using one of the 'WHEN CAN WE EXPECT ... " mes-

sages or a TXTD-2 (free text) message rather than resending the downlink message. Alter-
natively, the flight crew may use voice communication to clarify the status of the open
CPDLC downlink message; or

b. for an ATN-B1 aircraft, the flight crew should use voice communication to resolve the opera-

tional situation resulting from the timed out CPDLC downlink message.
NOTE 1: A closure response is a response that operationally closes the dialogue. A RSPU-2
STANDBY response to an open CPDLC downlink message does not operationally close the
dialogue.
NOTE 2: The use of a CPDLC free text message by a FANS 1/A aircraft avoids multiple
open messages involving the same downlink message.
NOTE 3: ATN-B1 ground systems will reject duplicate requests and return an ERROR mes-
sage for display to the flight crew TOO MANY (dialogue type) REQUESTS - EXPECT ONLY
ONE REPLY.

4.4

4.4.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1395

DATA LINK OPERATIONS

Example:

Flight crew

LVLD-2 REQUEST CLIMB TO FL350

Reasonable period of time has passed

Flight crew

LVLD-7 WHEN CAN WE EXPECT HIGHER LEVEL
or
TXTD-2 WHEN CAN WE EXPECT CLIMB TO FL350

4.4.1.6 If the flight crew receives an indication of non-delivery of a downlink message, they may
elect to re-send an identical message within a reasonable amount of time or as required. Alterna-
tively, they may use voice communication to clarify the status of the downlink message.

Free text

NOTE: Provisions concerning the use of free text messages elements are contained in Annex 10,
Volume II,8.2.11 and Doc 4444, 14.3.4.
4.4.2.1  While the use of free text should generally be avoided, the flight crew may use the free
text message element in accordance with the guidelines provided in this section.
NOTE 1: The use of standard message elements is intended to reduce the possibility of misinter-
pretation and ambiguity.
NOTE 2: A free text message (such as TXTD-2 REVISED ETA (position) (time)) does not require
a response from the ATS unit.
4.4.2.2  The flight crew should only use a free text message element when an appropriate stand-
ard message element does not exist.
4.4.2.3  When composing a free text message, the flight crew should use standard ATS phrase-
ology and format and avoid nonessential words and phrases. Abbreviations should only be inclu-
ded in free text messages when they form part of standard ICAO phraseology, for example, ETA.

Unsupported messages and voice responses to CPDLC requests

4.4.3.1  While ATS units should provide CPDLC service using the complete message set provi-
ded in Appendix A, some ATS units provide a CPDLC service using a limited message set. The
flight crew should be are aware of any unsupported downlink message elements that are descri-
bed in regional or State documentation.
4.4.3.2  If a downlink message, containing a message element that is not supported by the
ATSU, is sent, the flight crew will typically receive the uplink message, SYSU-3 MESSAGE NOT
SUPPORTED BY THIS ATC UNIT. If this message is received, the flight crew should respond to
the message with RSPD-4 ROGER and use voice for the communication transaction.
4.4.3.3  In circumstances where a CPDLC downlink message contains a request that can only
be responded to verbally, the flight crew will typically receive the CPDLC free text message
TXTU-1 REQUEST RECEIVED EXPECT VOICE RESPONSE to indicate that the operational

4.4.2

4.4.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1396

DATA LINK OPERATIONS

response will be via voice and to close the CPDLC dialogue. If this message is received, the flight
crew should respond to the message with RSPD-4 ROGER.
Example:

Controller

TXTU-1 REQUEST RECEIVED EXPECT VOICE RESPONSE

Flight crew

RSPD-4 ROGER

CPDLC reports and confirmation requests

4.4.4.1 The flight crew should respond to CPDLC reports and confirmation requests, when
appropriate.
4.4.4.2 ATS units may send a CPDLC message that combines a REPORT instruction with a
clearance. The flight crew may use automation, procedures, and/or a combination to remind them
when to send the reports requested in the CPDLC message.
Example:

Controller

LVLU-6 CLIMB TO FL350
LVLU-23 REPORT LEAVING FL330
LVLU-24 REPORT MAINTAINING FL350

Flight crew

RSPD-1 WILCO

4.4.4.3 The controller may send a CPDLC message to request the flight crew to advise inten-
tions when ADS-C indicates the aircraft has deviated from its cleared route, level or assigned
speed.

Weather deviations and offsets

General

4.4.5.1.1 The flight crew may use CPDLC to request a weather deviation clearance or an offset
clearance. The difference between a weather deviation and an offset are portrayed in Figure 4-2.

a. a weather deviation clearance authorizes the flight crew to deviate up to the specified dis-

tance at their discretion in the specified direction from the route in the flight plan; and

b. an offset clearance authorizes the flight crew to operate at the specified distance in the

specified direction from the route in the flight plan. A clearance is required to deviate from
this offset route.
NOTE: CPDLC offers more timely coordination of weather deviation clearances. However,
the flight crew may deviate due to weather under the provisions of ICAO Doc 4444, para-
graph 15.2.3. The extent to which weather deviations are conducted may be a consideration
when applying reduced separations.

4.4.5.1.2 Flight crews should use the correct message element when requesting an off-route
clearance.

4.4.4

4.4.5

4.4.5.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1397

DATA LINK OPERATIONS

NOTE: The difference between a weather deviation and an offset affects how ATC separate air-
craft.

Figure 4-2. Offset and weather deviation

Weather deviation requests and offsets

When requesting a weather deviation or offset clearance, the flight crew should specify the dis-
tance off route with respect to the cleared route of the aircraft. If the flight crew has received a off-
route clearance and then requests and receives a subsequent off-route clearance, the new clear-
ance supersedes the previous clearance (i.e. only the most recent clearance is valid).
NOTE: When an off-route clearance has been received, the flight crew will need to ensure that
waypoints are sequenced correctly per paragraph 4.5.1.6.
EXAMPLE 1: As shown in Figure 4-3, the flight crew requests a weather deviation clearance to
operate up to 20NM (37km) left of route. The controller issues the appropriate clearance.

Flight crew

LATD-2 REQUEST WEATHER DEVIATION UP TO 20NM LEFT OF
ROUTE

Controller

LATU-10 CLEARED TO DEVIATE UP TO 20NM LEFT OF ROUTE
LATU-18 REPORT BACK ON ROUTE

Flight crew

RSPD-1 WILCO

Figure 4-3. Weather deviation clearance up to 20NM (37km) left of route

4.4.5.2

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1398

DATA LINK OPERATIONS

EXAMPLE 2: As shown in Figure 4-4, the flight crew is operating on a weather deviation clear-
ance up to 20NM (37km) left of route and then requests another weather deviation clearance to
operate up to a further 30NM (55.5km) left of route. They specify the deviation distance in the
clearance request based on the cleared route rather in relation to the current weather deviation
clearance. The controller issues the appropriate clearance.

Flight crew

LATD-2 REQUEST WEATHER DEVIATION UP TO 50NM LEFT OF
ROUTE

Controller

LATU-10 CLEARED TO DEVIATE UP TO 50NM LEFT OF ROUTE
LATU-18 REPORT BACK ON ROUTE

Flight crew

RSPD-1 WILCO

Figure 4-4. Subsequent weather deviation clearance up to 50NM (93km) left of route

EXAMPLE 3: As shown in Figure 4-5 the aircraft then requests a weather deviation clearance to
operate 30NM (55.5km) right of route. The controller issues the appropriate clearance. The flight
crew expeditiously navigates from one side of route to the other in accordance with the below
clearance.
NOTE: The ATS unit applies the appropriate separation standards during the maneuvers.

Flight crew

LATD-2 REQUEST WEATHER DEVIATION UP TO 30NM RIGHT OF
ROUTE

Controller

LATU-10 CLEARED TO DEVIATE UP TO 30NM RIGHT OF ROUTE
LATU-18 REPORT BACK ON ROUTE

Flight crew

RSPD-1 WILCO

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1399

DATA LINK OPERATIONS

Figure 4-5. Subsequent weather deviation clearance up to 30NM (55.5km) right of route

Deviations either side of route

When requesting a deviation on either side of route, the flight crew should request a weather devi-
ation left and right of route using LATD-2 REQUEST WEATHER DEVIATION UP TO (lateral devi-
ation) OF ROUTE.
EXAMPLE: The flight crew requests a deviation left and right of route. The controller issues the
appropriate clearance.

Flight crew

LATD-2 REQUEST WEATHER DEVIATION UP TO 20NM LEFT OF
ROUTE

Controller

LATU-10 CLEARED TO DEVIATE UP TO 20NM EITHER SIDE OF
ROUTE
LATU-18 REPORT BACK ON ROUTE

Flight crew

RSPD-1 WILCO

4.4.5.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1400

DATA LINK OPERATIONS

Reporting back on route

When the flight crew no longer needs the deviation clearance and is back on the cleared route,
the flight crew should send the report LATD-4 BACK ON ROUTE.

a. If during the weather deviation, the flight crew receives a clearance to proceed direct to a

waypoint – and the flight crew responds to the clearance with RSPD-1 WILCO – the aircraft
is considered to be on the cleared route. Therefore, the flight crew should send a LATD-4
BACK ON ROUTE report after they execute the “direct to” clearance; and

b. If the aircraft is off route during a weather deviation clearance and proceeding direct to a

waypoint on the cleared route, the flight crew should send a LATD-4 BACK ON ROUTE
report after the aircraft has sequenced the waypoint on the cleared route.

NOTE: If a LATD-4 BACK ON ROUTE report is received while the aircraft is still off route, the
incorrect information provided to ATC may affect the separation standards in use. Alternatively,
the flight crew may consider requesting a clearance direct to the waypoint – on receipt of the
uplink clearance, the procedure specified in item a) above applies.

CPDLC Postion Reporting

General

When using CPDLC to provide position information, the flight crew should report unnamed way-
points (latitudes/longitudes) using the ICAO format of nn[N/S]nnn[EIW] or, if both degrees and
minutes are required, nnnn[N/S]nnnnn[E/W].
NOTE: The flight crew and flight operations officers/dispatchers should not use the ARINC 424
format. ARINC 424 describes a five-character latitude/longitude format for aircraft navigation data-
bases (e.g. 10N40 describes a lat/long of 10N140W). The ATS unit may reject or be unable to
process any downlink message containing waypoint names in the ARINC 424 format.

Position reporting in a non-ADS-C environment

4.4.6.2.1 When ADS-C is not available, the flight crew should conduct position reporting by
voice or CPDLC. When using CPDLC, the flight crew should send RTED-5 POSITION REPORT
[position report] whenever an ATC waypoint is sequenced, (or passed abeam when offset flight is
in progress).
4.4.6.2.2 When using CPDLC for position reporting, the flight crew should send position reports
only at compulsory reporting points and ensure that the position and next position information
applies to compulsory reporting points, unless requested otherwise by ATC. The ensuing signifi-
cant point after the next position may be either a compulsory or non-compulsory reporting point
(Refer AIREP form ICAO Doc 4444, Appendix 1).

Position reporting in an ADS-C environment

NOTE: In an ADS-C environment, the flight crew should not provide position reports or revised
waypoint estimates by CPDLC or voice, unless otherwise instructed or under conditions in certain
airspace as stipulated in Regional Supplementary Procedures or AIP (or other appropriate publi-
cation).

4.4.5.4

4.4.6

4.4.6.1

4.4.6.2

4.4.6.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1401

DATA LINK OPERATIONS

4.4.6.3.1 If required by regional supplementary procedures or AIP (or other appropriate publica-
tion), the flight crew should provide a CPDLC position report when either of the following events
occurs:

a. an initial CPDLC connection is established; or
b. the CPDLC connection transfer has been completed (i.e. at the associated boundary entry

position).

NOTE: Some ANSPs require a single CPDLC position report, even when in an ADS-C environ-
ment, to provide the controlling ATSU confirmation that it is the CDA and the only ATSU able to
communicate with the aircraft via CPDLC.
4.4.6.3.2  The flight crew should include only ATC waypoints in cleared segments of the aircraft
active flight plan. However, when an ATC clearance eliminates a waypoint, it is permissible to
retain and report the point abeam of that waypoint since this ensures retention of meteorological
data associated with the eliminated waypoint.
NOTE: If the flight crew inserts non-ATC waypoints (e.g. mid-points) into the aircraft active flight
plan and activates the change, the aircraft system may trigger an ADS-C waypoint change event
report at the non-ATC waypoint, or include information about the non-ATC waypoint in the predic-
ted route group, as well as the intermediate and fixed projected intent groups. As a result, the
ADS-C report will include information about the non-ATC waypoint, which is not expected by the
ATC ground system.
4.4.6.3.3  The flight crew should maintain the active route in the aircraft system to be the same
as the ATC cleared route of flight.
NOTE: If the flight crew activates a non-ATC cleared route into the aircraft system, the ADS-C
reports will include information that will indicate the aircraft is flying a route that is deviating from
the cleared route.
4.4.6.3.4  When reporting by ADS-C only, the flight crew should include ATC waypoints in the
aircraft active flight plan even if they are not compulsory reporting points.

AUTOMATIC DEPENDANT SURVEILLANCE – CONTRACT (ADS-C)

General

4.5.1.1 ADS-C allows the ATS unit to obtain position reports from the aircraft without flight crew
action to update the current flight plan, to check conformance and to provide emergency alerting.
NOTE: In airspace where ADS-C services are available, the flight crew need not send position
reports via voice or CPDLC, except as described in paragraph 4.4.6.3 or when required by
regional supplementary procedures or AIP (or other appropriate publication).
4.5.1.2 When using ADS-C services, the flight crew should check to ensure ADS-C is armed
prior to initiating a logon with an ATS unit.
NOTE: The flight crew can switch ADS-C off, which will cancel any ADS-C connections with the
aircraft. While ADS-C is disabled, the ground system will not be able to establish an ADS-C con-
nection.

4.5

4.5.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1402

DATA LINK OPERATIONS

4.5.1.3  Normally, the flight crew should leave ADS-C armed for the entire flight. However, in air-
space where ADS-C services are available, if the flight crew switches ADS-C off for any reason,
or they receive indication of avionics failure leading to loss of ADS-C service, the flight crew
should advise ATC and follow alternative procedures for position reporting per paragraphs 4.4.6
and 4.7.4.5.
4.5.1.4  In airspace where ADS-C is not available, the flight crew may switch ADS-C off to cancel
inadvertent ADS-C connections. In such cases, the flight crew should ensure that ADS-C is
armed when re-entering airspace where ADS-C is again available.
4.5.1.5  If ADS-C is disabled in an ADS-C environment, the ATS unit may send the flight crew an
inquiry per paragraph 4.7.4.7.
4.5.1.6  The flight crew should ensure that waypoints are sequenced correctly. If an aircraft
passes abeam a waypoint by more than the aircraft FMS waypoint sequencing parameter, the
flight crew should sequence the waypoints in the FMS, as appropriate.
NOTE: As shown in Figure 4-2, when an aircraft passes abeam a waypoint in excess of the
defined sequencing parameter for specific aircraft types, the FMS will not sequence the active
waypoint. If the flight crew does not sequence the waypoint, incorrect information will be con-
tained in ADS-C reports, CPDLC position reports and FMC waypoint position reports – the next
waypoint in these reports will actually be the waypoint that the aircraft has already passed.

Figure 4-6. Waypoint sequencing anomaly

EMERGENCY PROCEDURES

General

4.6.1.1 In accordance with established emergency procedures, the ATS unit within whose air-
space the aircraft is operating remains in control of the flight. If the flight crew takes action con-
trary to a clearance that the controller has already coordinated with another sector or ATS unit
and further coordination is not possible in the time available, then the flight crew performs this
action under their emergency command authority.
4.6.1.2 The flight crew will use whatever means are appropriate (i.e. CPDLC and/or voice) to
communicate during an emergency.

4.6

4.6.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1403

DATA LINK OPERATIONS

4.6.1.3 During an emergency, the flight crew would normally revert to voice communications.
However, the flight crew may use CPDLC for emergency communications if it is either more expe-
dient or if voice contact cannot be established.
NOTE: For ATN B1 aircraft, emergency message elements are not supported. See Appendix A,
A.4.9, for a list of emergency message elements.

CPDLC and ADS-C emergency

4.6.2.1  When using CPDLC to indicate an emergency situation or degraded operations to an
ATS unit, the flight crew should use the CPDLC emergency downlink message, either EMGD-2
MAYDAY MAYDAY MAYDAY or EMGD-1 PAN PAN PAN.
NOTE 1: The flight crew may enter PERSONS on BOARD during preflight preparation, prior to
initiating a logon, or prior to sending the emergency message.
NOTE 2: The CPDLC emergency downlink message will automatically select the ADS-C function
to emergency mode. When a situation prohibits sending a CPDLC emergency message (e.g. in
an ADS-C only environment), the flight crew may activate ADS-C emergency mode directly via
ADS-C control functions.
4.6.2.2  If a CPDLC emergency downlink message is inadvertently sent or the emergency situa-
tion is resolved, the flight crew should send EMGD-4 CANCEL EMERGENCY as soon as possi-
ble to advise the controller and automatically set the ADS-C emergency mode to off. After send-
ing EMGD-4 CANCEL EMERGENCY, the flight crew should confirm the status of the flight and
their intentions via either voice or CPDLC.
4.6.2.3  To check for inadvertent activation of the ADS-C emergency mode using CPDLC, the
controller may send the following CPDLC free text uplink or use equivalent voice phraseology.
The flight crew should then check the status of the aircraft’s ADS-C emergency mode and if the
emergency mode has been activated inadvertently, the flight crew should select ADS-C emer-
gency mode to off and advise the controller either by voice or by the following CPDLC messages.

Controller

EMGU-3 CONFIRM ADS-C EMERGENCY

Flight crew

RSPD-4 ROGER, then (free text)
TXTD-2 ADS-C RESET

NON-ROUTINE PROCEDURES

General

NOTE: Provisions concerning complete communications failure (CPDLC and voice) are contained
in Annex 2, 3.6.5.2, Annex 10, Volume II, 5.2.2.7 and Doc 4444, 15.3.

Voice communications related to data link

4.7.2.1 When CPDLC fails and open messages existed at the time of failure, the flight crew
should recommence any dialogues involving those messages by voice

4.6.2

4.7

4.7.1

4.7.2

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1404

DATA LINK OPERATIONS

4.7.2.2 The flight crew should use the standard voice phraseology under certain conditions as
indicated in Table 4-3.
4.7.2.3 Voice communication procedures related to data link operations are not standardized
among the regions. Refer to Appendix B, for additional voice communication procedures for a
specific region.

Table4-3. Voice phraseology related to CPDLC

Condition

Voice phraseology

To notify ATC of a correction to a CPDLC mes-
sage. (Doc 4444)

DISREGARD CPDLC (message type) MES-
SAGE, BREAK (correct information or request)

To notify ATC of a single CPDLC message fail-
ure. (Doc 4444)

CPDLC MESSAGE FAILURE (appropriate in-
formation or request)

To notify ATC of an aircraft data link system or
CPDLC connection failure. (Doc 4444)

CPDLC FAILURE (requests/notifications)
NOTE: This phraseology is included only with
the first transmission made for this reason.
EXAMPLE: CPDLC FAILURE. CONTINUING
ON VOICE.

To advise ATC that the CPDLC connection is
being terminated manually and logon proce-
dure is being initiated with the next ATSU.

DISCONNECTED CPDLC WITH (facility desig-
nation). LOGGING ON TO (facility designation)
NOTE: The facility designation is the ICAO
four-character facility code or facility name.

To advise ATC that a logon procedure is being
initiated following restoration of data link serv-
ice.

LOGGING ON TO (facility designation)

To advise ATC that a delayed CPDLC uplink
has been received and to request clarification
of the intent of the CPDLC message.

DELAYED CPDLC MESSAGE RECEIVED (re-
quests)
NOTE: See paragraph 4.2.1.9 for associated
procedures.

Data link initiation failure

NOTE: Provisions concerning the data link initiation failure are contained in Annex 10, Volume II,
8. 1.1.4 and Doc 4444, 4.15.4.
4.7.3.1 In the event of a logon failure, the flight crew should confirm the aircraft identification
matches the information provided in the FPL and, as appropriate:

a. make the necessary corrections; and then
b. re-initiate the logon.

4.7.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1405

DATA LINK OPERATIONS

4.7.3.2 If no reason for the failure is evident, the flight crew should:

a. contact the ATSU by voice to advise of the failure; and
b. contact AOC to advise of the failure.

NOTE: The ATS unit will attempt to resolve the problem.
4.7.3.3 The flight crew should report log-on failures to the appropriate local/regional monitoring
agency in accordance with procedures established by the operator.

Data link system failures

4.7.4.1 When SATCOM is not serviceable, the flight crew may use CPDLC within VHF coverage
unless restricted by State AlP and/or SUPPS.
4.7.4.2 When operating CPDLC and the aircraft data link system provides an indication of
degraded performance resulting from a failure or loss of connectivity, the flight crew should notify
the ATSU of the failure as soon as practicable, including:

a. when operating outside of VHF coverage area and the SATCOM data link system fails; and
b. when operating in airspace where ATS surveillance services are provided and the VHF data

link system fails.

NOTE: Timely notification is appropriate to ensure that the ATS unit has time to assess the situa-
tion and apply a revised separation standard, if necessary.
4.7.4.3 If an automatic transfer of the CPDLC connection does not occur at the boundary, the
flight crew should contact the transferring ATS unit by sending TXTD-2 CPDLC TRANSFER FAIL-
URE (or voice equivalent), advising them that the transfer has not occurred. The flight crew may
be instructed to reinitiate a logon.
4.7.4.4. In the event of an aircraft data link system failure, the flight crew should notify the ATSU
of the situation using the following voice phraseology:

Flight crew

CPDLC FAILURE. CONTINUING ON VOICE

Controller

ROGER. CONTINUE ON VOICE

NOTE: The flight crew continues to use voice until the functionality of the aircraft system can be
re-established.
4.7.4.5  When the ATS unit provides notification that the CPDLC service has failed or will be shut
down, the flight crew should follow the instructions provided in the notification (e.g. disconnect
CPDLC and continue on voice until informed by the ATSU that the data link system has resumed
normal CPDLC operations).
4.7.4.6  If only the ADS-C service is terminated, then during that time period, the flight crew
should conduct position reporting by other means (e.g. CPDLC, if available, or via voice).
4.7.4.7  If the ATS unit cannot establish ADS contracts with an aircraft, or if ADS-C reporting
from an aircraft ceases, the flight crew may have inadvertently switched ADS-C off. If CPDLC is

4.7.4

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1406

DATA LINK OPERATIONS

still available and the flight crew receives the CPDLC message ADVU-16 ACTIVATE ADS-C (or
voice equivalent), the crew should check to ensure that ADS-C is not switched off and respond to
the controller as follows:

Controller

ADVU-16 ACTIVATE ADS-C

Flight crew

RSPD-4 ROGER

4.7.4.8 If the aircraft is operating on a vertical profile that is different from the profile program-
med in the FMS, the time estimates in the ADS-C report will be inaccurate. If the flight crew
receives the message TXTU-1 ADS-C ESTIMATES APPEAR INACCURATE. CHECK FMS, the
flight crew should check the FMS, correct any the discrepancy and respond to the CPDLC mes-
sage with RSPD-4 ROGER.

Using CPDLC to relay messages

4.7.5.1 When an ATS unit and an aircraft cannot communicate, the controller may use CPDLC
or voice to relay messages. When it had been determined to use CPDLC, the controller may first
confirm that the CPDLC-capable aircraft is in contact with the subject aircraft. The flight crew
should concur that they will act as an intermediary.
4.7.5.2 When using CPDLC to relay messages, the flight crew should:

a. Only respond with RSPD-4 ROGER to CPDLC messages consisting entirely of free text; and
b. Respond with RSPD-2 UNABLE to any CPDLC message containing standard message ele-

ments to avoid confusion.

4.7.5.3 After sending RSPD-4 ROGER, the flight crew should only use free text to respond to
the controller’s uplink free text message.
Example, using:

a. ADVU-18 RELAY TO (aircraft identification) (unit name) (relay text) (frequency(O)); and
b. COMD-2 RELAY FROM (aircraft identification) (relayed text response); where:

1. (aircraft identification) is expressed as the radiotelephony call sign, rather than the

ICAO three letter or IATA two letter designator; and

2. (relay text) conform to the guidelines provided paragraph 4.4.2.3.

Controller

ADVU-18 RELAY TO UNITED345 OAKLAND CLEARS UNITED345
CLIMB TO AND MAINTAIN FL340

Flight crew

RSPD-4 ROGER

Flight crew

COMD-2 RELAY FROM UNITED345 CLIMBING FL340

4.7.5

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1407

DATA LINK OPERATIONS

DLIC AND CPDLC MESSAGE ELEMENTS

General

A.1.1 This appendix contains the CPDLC message elements for the FANS 1/A, ATN B1, and
ATN B1-FANS 1/A data link systems. The CPDLC message elements are based on the CPDLC
message set in Doc 4444, Amendment 7.
A.1.2 The following guidelines apply:

a. “operational definition columns” are taken from Doc 4444 (e.g. message element intended

use, format for message element display and message response attribute). The message
elements shaded in grey indicate that they are currently under consideration for inclusion as
part of future amendments to Doc 4444.

b. the “CPDLC message sets” columns indicate which message element in each CPDLC mes-

sage set, i.e. FANS 1/A, ATN B1, or ATN B1-FANS 1/A supports the message element indi-
cated in Doc 4444. The annotation N/A in the “CPDLC message set” column indicates that
the corresponding CPDLC message set does not support the message element defined in
Doc 4444.

c. where there are differences with Doc 4444 in regard to format for message element display,

the recommended choice indicated in Doc 4444 should be used for new implementations.
The others shown in the technology-specific columns indicate legacy implementations that
are considered acceptable.
NOTE: When a FANS 1/A and/or ATN B1 free text message element is used to provide the
operational intended use equivalent to a standard message element as defined in Doc 4444,
this manual provides the recommended content for the free text message element in the
FANS 1/A and/or ATN B1 columns. In some cases, this guidance might differ from the con-
tent specified in the supporting interoperability standards.

d. a FANS 1/A and/or ATN B1 message element that does not have an equivalent message

element in Doc 4444 should not be used. New FANS 1/A and/or ATN B1 implementations
may reject these message elements, indicating they are not supported.

e. The CPDLC message set in use will depend on the aircraft system and ground system capa-

bilities and is shown as follows:

Aircraft system

FANS 1/A

ATN B1

FANS 1/A-ATN
B1

Ground System

FANS 1/A

FANS 1/A

N/A

FANS 1/A

ATN B1

N/A

ATN B1

Appendix A -

A.1 -

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1408

DATA LINK OPERATIONS

JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21) - page 44