JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21)

Aircraft system

FANS 1/A - ATN
B1

ATN B1

ATN B1 or FANS
1/A-ATN B1

A FANS 1/A-ATN B1 aircraft system fully supports FANS 1/A and ATN B1 CPDLC message
sets.
The FANS 1/A-ATN B1 message set is the equivalent of an ATN B1 message set either
through the use of:
a) free text message elements (e.g. UM 169, DM 67); and/or
b) other message elements that are operationally equivalent.

MESSAGES FOR DLIC AND CPDLC CONNECTION ESTABLISHMENT/

TERMINATION

Air-ground data link messages for DLIC

Generic message

name

Purpose

FANS 1/A

ATN B1

Air-ground logon procedure
Logon Request

To provide the ATSU
with information to
confirm the identity of
the aircraft and its data
link capabilities, and to
notify the ATSU of the
flight crew's intention
to use data link serv-
ices.

FN_CON

CM_LOGON_RE-
QUEST

Logon response

To notify the aircraft of
the status of its logon
request.

FN_AK

CM_LOGON_RE-
SPONSE

Air-ground address forwarding procedure
Contact Request

To instruct the aircraft
to send a logon re-
quest to the specified
ATSU.

FN_CAD

CM_CONTACT

A.2

A.2.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1409

DATA LINK OPERATIONS

Generic message

name

Purpose

FANS 1/A

ATN B1

Contact Response

To indicate to the ini-
tiating ATSU that the
logon request will be
sent to the specified
ATSU.

FN_RESP

No ATN equivalent

Contact Complete

To provide to the ini-
tiating ATSU the status
of the logon request to
the specified ATSU.

FN_COMP

CM_CONTACT_RE-
SPONSE

RESPONSE ATTRIBUTE OF CPDLC MESSAGE ELEMENT

Response
Attribute

Description

For Uplink Message

W/U

Response required.
Valid responses. WILCO, UNABLE, STANDBY, NOT CURRENT DATA AUTHORI-
TY, NOT AUTHORIZED NEXT DATA AUTHORITY, LOGICAL ACKNOWLEDGE-
MENT (only if required), ERROR
NOTE: WILCO, UNABLE, NOT CURRENT DATA AUTHORITY, NOT AUTHOR-
IZED NEXT DATA AUTHORITY and ERROR will close the uplink message.
FANS 1/A. — WILCO, UNABLE, STANDBY, ERROR, NOT CURRENT DATA AU-
THORITY.

A/N

Response required.
Valid responses. AFFIRM, NEGATIVE, STANDBY, NOT CURRENT DATA AU-
THORITY, NOT AUTHORIZED NEXT DATA AUTHORITY, LOGICAL ACKNOWL-
EDGEMENT (only if required), ERROR
NOTE: AFFIRM, NEGATIVE, NOT CURRENT DATA AUTHORITY, NOT AUTHOR-
IZED NEXT DATA AUTHORITY and ERROR will close the uplink message.
FANS 1/A. — AFFIRM, NEGATIVE, STANDBY, ERROR, NOT CURRENT DATA
AUTHORITY.

A.3 -

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1410

DATA LINK OPERATIONS

Response
Attribute

Description

For Uplink Message

Response required.
Valid responses. ROGER, UNABLE, STANDBY, NOT CURRENT DATA AUTHORI-
TY, NOT AUTHORIZED NEXT DATA AUTHORITY, LOGICAL ACKNOWLEDGE-
MENT (only if required), ERROR
NOTE: ROGER, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT
DATA AUTHORITY and ERROR will close the uplink message.
FANS 1/A. — ROGER, STANDBY, ERROR, NOT CURRENT DATA AUTHORITY.
FANS 1/A aircraft do not have the capability to send UNABLE in response to an up-
link message containing message elements with an “R” response attribute. For
these aircraft, the flight crew may use alternative means to UNABLE the message.
These alternative means will need to be taken into consideration to ensure proper
technical and operational closure of the communication transaction.

Response required.
Valid responses: Any CPDLC downlink message, LOGICAL ACKNOWLEDGE-
MENT (only if required).

No response required unless logical acknowledgement required.
Valid Responses (only if LOGICAL ACKNOWLEDGEMENT is required). LOGICAL
ACKNOWLEDGEMENT, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED
NEXT DATA AUTHORITY, ERROR
FANS 1/A. — "N" is defined as “no response is required,“ but not used. Under some
circumstances, an ERROR message will also close an uplink message.

[Not defined in ICAO Doc 4444]
FANS 1/A. — The WILCO, UNABLE, AFFIRM, NEGATIVE, ROGER, and STAND-
BY responses are not enabled (NE) for flight crew selection. An uplink message with
a response attribute NE is considered to be closed even though a response may be
required operationally. Under some circumstances, a downlink error message may
be linked to an uplink message with a NE attribute.

For Downlink Messages

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1411

DATA LINK OPERATIONS

Response
Attribute

Description

For Uplink Message

Response required. Yes
Valid responses. Any CPDLC uplink message, LOGICAL ACKNOWLEDGEMENT
(only if required).

Response required. No, unless logical acknowledgement required.
Valid responses (only if LOGICAL ACKNOWLEDGEMENT is required). LOGICAL
ACKNOWLEDGEMENT, SERVICE UNAVAILABLE, FLIGHT PLAN NOT HELD, ER-
ROR
FANS 1/A. — Aircraft do not have the capability to receive technical responses to
downlink message elements with an “N” response attribute (other than LACK or ER-
ROR for ATN B1 aircraft). In some cases, the response attribute is different between
FANS 1/A aircraft and ICAO Doc 4444. As an example, most emergency messages
have an “N” response attribute for FANS 1/A whereas ICAO Doc 4444 defines a “Y”
response attribute for them. As a consequence, for FANS 1/A aircraft, the ATC will
need to use alternative means to acknowledge to the flight crew that an emergency
message has been received.

CPDLC MESSAGE ELEMENTS

NOTE 1: The [O] attached to a parameter indicates that the provision of this parameter in the
message element is optional.
NOTE 2: The message text within parenthesis (e.g. (TERMINATE AT (position Atw[O])) as part of
SPCU-11) indicates that the provision of this text and associated parameter in the message ele-
ment is optional.

Route message elements

Route uplink message elements (RTEU)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message
element
identifier

Message ele-
ment intended
use

Format for mes-
sage element
display

Resp. FANS 1/A

ATN B1

A.4 –

A.4.1

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1412

DATA LINK OPERATIONS

Route uplink message elements (RTEU) (continued)

RTEU-1

Instruction to
proceed via the
specified depar-
ture clearance.

(departure clear-
ance)

W/U

UM169 (free text)
NOTE: UM169
may be combined
with UM158 ATIS
(atis code) and/or
UM123 SQUAWK
(beacon) code)
and/or UM19
MAINTAIN (alti-
tude).

N/A

RTEU-2

Instruction to
proceed directly
to the specified
position.

PROCEED DI-
RECT TO (posi-
tion)

W/U

UM74 PROCEED
DIRECT TO (posi-
tion)

UM75 WHEN
ABLE PROCEED
DIRECT TO (posi-
tion)
NOTE: This mes-
sage element is
equivalent to SU-
PU-5 plus RTEU-2
in Doc 4444.

N/A

RTEU-3

Instruction to
proceed, at the
specified time,
directly to the
specified posi-
tion.

AT TIME (time)
PROCEED DI-
RECT TO (posi-
tion)

W/U

UM76 AT (time)
PROCEED DI-
RECT TO (posi-
tion)

N/A

RTEU-4

Instruction to
proceed, at the
specified posi-
tion, directly to
the next speci-
fied position.

AT (position)
PROCEED DI-
RECT TO (posi-
tion)

W/U

UM77 AT (position)
PROCEED DI-
RECT TO (posi-
tion)

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1413

DATA LINK OPERATIONS

Route uplink message elements (RTEU) (continued)

RTEU-5

Instruction to
proceed upon
reaching the
specified level,
directly to the
specified posi-
tion.

AT (level single)
PROCEED DI-
RECT TO (posi-
tion)

W/U

UM78 AT (altitude)
PROCEED DI-
RECT to (position)

N/A

RTEU-6

Instruction to
proceed to the
specified posi-
tion via the
specified route.

CLEARED TO
(position) VIA
(departure da-
ta[O]) (en-route
data)

W/U

UM79 CLEARED
TO (position) VIA
(route clearance)

RTEU-7

Instruction to
proceed via the
specified route.

CLEARED (de-
parture data[O])
(en-route data)
(arrival approach
data)

W/U

UM80 CLEARED
(route clearance)

RTEU-8

Instruction to
proceed in ac-
cordance with
the specified
procedure.

CLEARED (pro-
cedure name)

W/U

UM81 CLEARED
(procedure name)

N/A

RTEU-9

Instruction to
proceed from
the specified po-
sition via the
specified route.

AT (position)
CLEARED (en-
route data) (ar-
rival approach
data)

W/U

UM83 AT (position)
CLEARED (route
clearance)

N/A

RTEU-10 Instruction to

proceed from
the specified po-
sition via the
specified proce-
dure.

AT (position)
CLEARED (pro-
cedure name)

W/U

UM84 AT (position)
CLEARED (proce-
dure name)

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1414

DATA LINK OPERATIONS

Route uplink message elements (RTEU) (continued)

RTEU-11 Instruction to en-

ter a holding pat-
tern at the speci-
fied position in
accordance with
the specified in-
structions.
NOTE: RTEU-13
EXPECT FUR-
THER CLEAR-
ANCE AT TIME
(time) is appen-
ded to this mes-
sage when an
extended hold is
anticipated.

AT (position)
HOLD INBOUND
TRACK (de-
grees) (direction)
TURNS (leg
type) LEGS

W/U

UM91 HOLD AT
(position) MAIN-
TAIN (altitude) IN-
BOUND TRACK
(degrees) (direc-
tion) TURN LEG
TIME (leg type)

N/A

RTEU-12 Instruction to en-

ter a holding pat-
tern at the speci-
fied position in
accordance with
the published
holding instruc-
tions.
NOTE: RTEU-13
EXPECT FUR-
THER CLEAR-
ANCE AT TIME
(time) is appen-
ded to this mes-
sage when an
extended hold is
anticipated.

AT (position)
HOLD AS PUB-
LISHED

W/U

UM92 HOLD AT
(position) AS PUB-
LISHED MAINTAIN
(altitude)

UM92 HOLD AT
(position) AS PUB-
LISHED MAINTAIN
(level)

RTEU-13 Notification that

an onwards
clearance may
be issued at the
specified time.

EXPECT FUR-
THER CLEAR-
ANCE AT TIME
(time)

UM93 EXPECT
FURTHER
CLEARANCE AT
(time)

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1415

DATA LINK OPERATIONS

Route uplink message elements (RTEU) (continued)

RTEU-14 Notification that

a clearance may
be issued for the
aircraft to fly the
specified proce-
dure or clear-
ance name.

EXPECT (named
instruction)

UM99 EXPECT
(procedure name)
NOTE: Used when
a published proce-
dure is designated.
UM169 ‘EXPECT
(clearance name)’
NOTE: Used when
an unpublished
clearance/proce-
dure name is des-
ignated.

N/A

RTEU-15 Request to con-

firm the as-
signed route.

CONFIRM AS-
SIGNED ROUTE

UM137 CONFIRM
ASSIGNED
ROUTE
NOTE: NE re-
sponse attribute.

N/A

RTEU-16 Request to

make a position
report.

REQUEST PO-
SITION RE-
PORT

UM147 REQUEST
POSITION RE-
PORT

N/A

RTEU-17 Request to pro-

vide the estima-
ted time of arriv-
al at the speci-
fied position.

ADVISE ETA
(position)

UM169 ‘ADVISE
ETA (position)’

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1416

DATA LINK OPERATIONS

Route downlink message elements (RTED)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message

element

identifier

Message ele-

ment intended

use

Format for mes-

sage element

display

Resp.

FANS 1/A

ATN B1

RTED-1

Request for a di-
rect clearance to
the specified po-
sition.

REQUEST DI-
RECT TO (posi-
tion)

DM22 REQUEST
DIRECT TO (posi-
tion)

RTED-2

Request for the
specified proce-
dure or clear-
ance name.

REQUEST
(named instruc-
tion)

DM23 REQUEST
(procedure name)

N/A

RTED-3

Request for the
specified route.

REQUEST
CLEARANCE
departure da-
ta[O]) (en-route
data) (arrival ap-
proach data[O])

DM24 REQUEST
(route clearance)

N/A

RTED-4

Request for the
specified clear-
ance.

REQUEST
(clearance type)
CLEARANCE

DM25 REQUEST
CLEARANCE

N/A

RTED-5

Position report.

POSITION RE-
PORT (position
report)

DM48 POSITION
REPORT (position
report)

N/A

RTED-6

Request for the
specified head-
ing.

REQUEST
HEADING (de-
grees)

DM70 REQUEST
HEADING (de-
grees)

N/A

RTED-7

Request for the
specified ground
track.

REQUEST
GROUND
TRACK (de-
grees)

DM71 REQUEST
GROUND TRACK
(degrees)

N/A

RTED-8

Request for the
time or position
that can be ex-
pected to rejoin
the cleared
route.

WHEN CAN WE
EXPECT BACK
ON ROUTE

DM51 WHEN CAN
WE EXPECT
BACK ON ROUTE

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1417

DATA LINK OPERATIONS

Route downlink message elements (RTED) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message

element

identifier

Message ele-

ment intended

use

Format for mes-

sage element

display

Resp.

FANS 1/A

ATN B1

RTED-9

Confirmation that
the assigned
route is the
specified route.

ASSIGNED
ROUTE (depar-
ture data[O])
(en-route data)
(arrival approach
data[O])

DM40 ASSIGNED
ROUTE (route
clearance)

N/A

RTED-10 Notification of

estimated time of
arrival at the
specified posi-
tion.

ETA (position)
TIME (time)

DM67 ‘ETA (posi-
tion) TIME (time)’

N/A

Lateral message elements

Lateral uplink message elements (LATU)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message
element
identifier

Message ele-
ment intended
use

Format for
message ele-
ment display

Resp. FANS 1/A

ATN B1

LATU-1

Instruction to fly
a parallel track to
the cleared route
at a displace-
ment of the
specified dis-
tance in the
specified direc-
tion.

OFFSET (speci-
fied distance)
(direction) OF
ROUTE

W/U

UM64 OFFSET
(distance offset)
(direction) OF
ROUTE

UM64 OFFSET
(specified distance)
(direction) OF
ROUTE

A.4.2

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1418

DATA LINK OPERATIONS

Lateral uplink message elements (LATU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LATU-2

Instruction to fly
a parallel track to
the cleared route
at a displace-
ment of the
specified dis-
tance in the
specified direc-
tion and com-
mencing at the
specified posi-
tion.

AT (position)
OFFSET speci-
fied distance)
(direction) OF
ROUTE

W/U

UM65 AT (position)
OFFSET (distance
offset) (direction)
OF ROUTE

N/A

LATU-3

Instruction to fly
a parallel track to
the cleared route
at a displace-
ment of the
specified dis-
tance in the
specified direc-
tion and com-
mencing at the
specified time.

AT TIME (time)
OFFSET (speci-
fied distance)
(direction) OF
ROUTE

W/U

UM66 AT (time)
OFFSET (distance
offset) (direction)
OF ROUTE

N/A

LATU-4

Instruction to re-
join the cleared
route.

REJOIN ROUTE W/U

UM67 PROCEED
BACK ON ROUTE

N/A

LATU-5

Instruction to re-
join the cleared
route before
passing the
specified posi-
tion.

REJOIN ROUTE
BEFORE PASS-
ING (position)

W/U

UM68 REJOIN
ROUTE BY (posi-
tion)

N/A

LATU-6

Instruction to re-
join the cleared
route before the
specified time.

REJOIN ROUTE
BEFORE TIME
(time)

W/U

UM69 REJOIN
ROUTE BY (time)

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1419

DATA LINK OPERATIONS

Lateral uplink message elements (LATU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LATU-7

Notification that
a clearance may
be issued to ena-
ble the aircraft to
rejoin the cleared
route before
passing the
specified posi-
tion.

EXPECT BACK
ON ROUTE BE-
FORE PASSING
(position)

UM70 EXPECT
BACK ON ROUTE
BY (position)

N/A

LATU-8

Notification that
a clearance may
be issued to ena-
ble the aircraft to
rejoin the cleared
route before the
specified time.

EXPECT BACK
ON ROUTE BE-
FORE TIME
(time)

UM71 EXPECT
BACK ON ROUTE
BY (time)

N/A

LATU-9

Instruction to re-
sume own navi-
gation following
a period of track-
ing or heading
clearances. May
be used in con-
junction with an
instruction on
how or where to
rejoin the cleared
route.

RESUME OWN
NAVIGATION

W/U

UM72 RESUME
OWN NAVIGA-
TION

LATU-10 Instruction allow-

ing deviation up
to the specified
distance(s) from
the cleared route
in the specified
direction(s).

CLEARED TO
DEVIATE UP
TO (lateral devi-
ation) OF
ROUTE

W/U

UM82 CLEARED
TO DEVIATE UP
TO (distance off-
set) (direction) OF
ROUTE

UM82 CLEARED
TO DEVIATE UP
TO TO (specified
distance) (direc-
tion) OF ROUTE

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1420

DATA LINK OPERATIONS

Lateral uplink message elements (LATU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LATU-11 Instruction to

turn left or right
as specified on
to the specified
heading.

TURN (direction)
HEADING (de-
grees)

W/U

UM94 TURN (di-
rection) HEADING
(degrees)

UM98 IMMEDI-
ATELY TURN (di-
rection) HEADING
(degrees) Note. -
This message ele-
ment is equivalent
to EMGU-2 plus
LATU-11 in Doc
4444.

N/A

LATU-12 Instruction to

turn left or right
as specified on
to the specified
track.

TURN (direction)
GROUND
TRACK (de-
grees)

W/U

UM95 TURN (di-
rection) GROUND
TRACK (degrees)

N/A

LATU-13 Instruction to

turn left or speci-
fied number of
degrees left or
right.

TURN (direction)
(number of de-
grees) DE-
GREES

W/U

N/A

UM215 TURN (di-
rection) (degrees)

LATU-14 Instruction to

continue to fly
the present
heading.

CONTINUE
PRESENT
HEADING

W/U

UM96 FLY
PRESENT HEAD-
ING

UM96 CONTINUE
PRESENT HEAD-
ING

LATU-15 Instruction to fly

the specified
heading upon
reaching the
specified posi-
tion.

AT (position)
FLY HEADING
(degrees)

W/U

UM97 AT (position)
FLY HEADING
(degrees)

N/A

LATU-16 Instruction to fly

the specified
heading.

FLY HEADING
(degrees)

W/U

N/A

UM190 FLY
HEADING (de-
grees)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1421

DATA LINK OPERATIONS

Lateral uplink message elements (LATU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LATU-17 Instruction to re-

port when clear
of weather.

REPORT
CLEAR OF
WEATHER

W/U

UM169 ‘REPORT
CLEAR OF
WEATHER’
NOTE: R response
attribute.

N/A

LATU-18 Instruction to re-

port when the
aircraft is back
on the cleared
route.

REPORT BACK
ON ROUTE

W/U

UM127 REPORT
BACK ON ROUTE
NOTE: R response
attribute.

N/A

LATU-19 Instruction to re-

port upon pass-
ing the specified
position.

REPORT PASS-
ING (position)

W/U

UM130 REPORT
PASSING (posi-
tion)
NOTE: R response
attribute.

N/A

Lateral downlink message elements (LATD)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message
element
identifier

Message ele-
ment intended
use

Format for
message ele-
ment display

Resp. FANS 1/A

ATN B1

LATD-1

Request for a
parallel track
from the cleared
route at a dis-
placement of the
specified dis-
tance in the
specified direc-
tion.

REQUEST OFF-
SET (specified
distance) (direc-
tion) OF ROUTE

DM15 REQUEST
OFFSET (specified
distance) (direc-
tion) OF ROUTE

N/A

LATD-2

Request for a
weather devia-
tion up to the
specified dis-
tance(s) off track
in the specified
direction(s).

REQUEST
WEATHER DE-
VIATION UP TO
(lateral devia-
tion) OF ROUTE

DM27 REQUEST
WEATHER DEVIA-
TION UP TO
(specified distance)
(direction) OF
ROUTE

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1422

DATA LINK OPERATIONS

Lateral downlink message elements (LATD) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LATD-3

Report indicating
that the aircraft is
clear of weather.

CLEAR OF
WEATHER

DM69 ‘CLEAR OF
WEATHER’

N/A

LATD-4

Report indicating
that the cleared
route has been
rejoined.

BACK ON
ROUTE

DM41 BACK ON
ROUTE

N/A

LATD-5

Report indicating
diverting to the
specified position
via the specified
route, which may
be sent without
any previous co-
ordination done
with ATC.

DIVERTING TO
(position) VIA
(en-route data)
(arrival approach
data[O])

DM59 DIVERTING
TO (position) VIA
(route clearance)
NOTE 1: H alert at-
tribute.
NOTE 2: N re-
sponse attribute.

N/A

LATD-6

Report indicating
that the aircraft is
offsetting to a
parallel track at
the specified dis-
tance in the
specified direc-
tion off from the
cleared route.

OFFSETTING
(specified dis-
tance) (direction)
OF ROUTE

DM60 OFFSET-
TING (distance off-
set) (direction) OF
ROUTE
NOTE 1: H alert at-
tribute.
NOTE 2: N re-
sponse attribute.

N/A

LATD-7

Report indicating
deviating speci-
fied distance or
degrees in the
specified direc-
tion from the
cleared route.

DEVIATING
(specified Devia-
tion) (direction)
OF ROUTE

DM80 DEVIATING
(deviation Offset)
(direction) OF
ROUTE
NOTE 1: H alert at-
tribute.
NOTE 2: N re-
sponse attribute.

N/A

LATD-8

Report indicating
passing the
specified posi-
tion.

PASSING (posi-
tion)

DM31 PASSING
(position)

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1423

DATA LINK OPERATIONS

Level message elements

Level uplink message elements (LVLU)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message
element
identifier

Message ele-
ment intended
use

Format for
message ele-
ment display

Resp. FANS 1/A

ATN B1

LVLU-1

Notification that
an instruction
may be expected
for the aircraft to
commence climb
at the specified
time.

EXPECT HIGH-
ER AT TIME
(time)

UM7 EXPECT
CLIMB AT (time)

N/A

LVLU-2

Notification that
an instruction
may be expected
for the aircraft to
commence climb
at the specified
position.

EXPECT HIGH-
ER AT (position)

UM8 EXPECT
CLIMB AT (posi-
tion)

N/A

LVLU-3

Notification that
an instruction
may be expected
for the aircraft to
commence de-
scent at the
specified time.

EXPECT LOW-
ER AT TIME
(time)

UM9 EXPECT DE-
SCENT AT (time)

N/A

LVLU-4

Notification that
an instruction
may be expected
for the aircraft to
commence de-
scent at the
specified posi-
tion.

EXPECT LOW-
ER AT (position)

UM10 EXPECT
DESCENT AT (po-
sition)

N/A

LVLU-5

Instruction to
maintain the
specified level or
vertical range.

MAINTAIN (lev-
el)

W/U

UM19 MAINTAIN
(altitude)
NOTE: Used for a
single level.

UM19 MAINTAIN
(level)

A.4.3

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1424

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

UM30 MAINTAIN
BLOCK (altitude)
TO (altitude)
NOTE: Used for a
vertical range.

LVLU-6

Instruction that a
climb to the
specified level or
vertical range is
to commence
and once
reached is to be
maintained.

CLIMB TO (lev-
el)

W/U

UM20 CLIMB TO
AND MAINTAIN
(altitude)
NOTE: Used for a
single level.

UM20 CLIMB TO
(level)

UM31 CLIMB TO
AND MAINTAIN
BLOCK (altitude)
TO (altitude)
NOTE: Used for a
vertical range.

UM36 EXPEDITE
CLIMB TO (alti-
tude)
NOTE: This mes-
sage element is
equivalent to SU-
PU-3 plus LVLU-6
in Doc 4444.

N/A

UM38 IMMEDI-
ATELY CLIMB TO
(altitude)
NOTE: This mes-
sage element is
equivalent to EM-
GU-2 plus LVLU-6
in Doc 4444.

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1425

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-7

Instruction that
at the specified
time a climb to
the specified lev-
el or vertical
range is to com-
mence and once
reached is to be
maintained.
NOTE: This
message ele-
ment would be
preceded with
LVLU-5 MAIN-
TAIN (level) to
prevent the pre-
mature execu-
tion of the in-
struction.

AT TIME (time)
CLIMB TO (lev-
el)

W/U

UM21 AT (time)
CLIMB TO AND
MAINTAIN (alti-
tude)
NOTE: A vertical
range can not be
provided.

N/A

LVLU-8

Instruction that
at the specified
position a climb
to the specified
level or vertical
range is to com-
mence and once
reached is to be
maintained.
NOTE: This
message ele-
ment would be
preceded with
LVLU-5 MAIN-
TAIN (level) to
prevent the pre-
mature execu-
tion of the in-
struction.

AT (position)
CLIMB TO (lev-
el)

W/U

UM22 AT (position)
CLIMB TO AND
MAINTAIN (alti-
tude)
NOTE: A vertical
range can not be
provided.

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1426

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-9

Instruction that a
descent to the
specified level or
vertical range is
to commence
and once
reached is to be
maintained.

DESCEND TO
(level)

W/U

UM23 DESCEND
TO AND MAIN-
TAIN (altitude)
NOTE: Used for a
single level.

UM23 DESCEND
TO (level)

UM32 DESCEND
TO. AND MAIN-
TAIN BLOCK (alti-
tude) TO (altitude)
NOTE: Used for a
vertical range.

UM37 EXPEDITE
DESCENT TO (al-
titude)

UM39 IMMEDI-
ATELY DESCEND
TO (altitude)
NOTE: This mes-
sage element is
equivalent to EM-
GU-2 plus LVLU-9
in Doc 4444.

N/A

LVLU-10 Instruction that

at the specified
time a descent to
the specified lev-
el or vertical
range is to com-
mence and once
reached is to be
maintained.

AT TIME (time)
DESCEND TO
(level)

W/U

UM24 AT (time)
DESCEND TO
AND MAINTAIN
(altitude)
NOTE: A vertical
range can not be
provided.

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1427

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-11 Instruction that

at the specified
position a de-
scent to the
specified level or
vertical range is
to commence
and once
reached is to be
maintained.

AT (position)
DESCEND TO
(level)

W/U

UM25 AT (position)
DESCEND TO
AND MAINTAIN
(altitude)
NOTE: A vertical
range can not be
provided.

N/A

LVLU-12 Instruction that a

climb is to be
completed such
that the specified
level is reached
before the speci-
fied time.

CLIMB TO
REACH (level
single) BEFORE
TIME (time)

W/U

UM26 CLIMB TO
REACH (altitude)
BY (time)

UM26 CLIMB TO
REACH (level) BY
(time)

LVLU-13 Instruction that a

climb is to be
completed such
that the specified
level is reached
before the speci-
fied position.

CLIMB TO
REACH (level
single) BEFORE
PASSING (posi-
tion)

W/U

UM27 CLIMB TO
REACH (altitude)
BY (position)

UM27 CLIMB TO
REACH (level) BY
(position)

LVLU-14 Instruction that a

descent is to be
completed such
that the specified
level is reached
before the speci-
fied time.

DESCEND TO
REACH (level
single) BEFORE
TIME (time)

W/U

UM28 DESCEND
TO REACH (alti-
tude) BY (time)

UM28 DESCEND
TO REACH (level)
BY (time)

LVLU-15 Instruction that a

descent is to be
completed such
that the specified
level is reached
before the speci-
fied position.

DESCEND TO
REACH (level
single) BEFORE
PASSING (posi-
tion)

W/U

UM29 DESCEND
TO REACH (alti-
tude) BY (position)

UM29 DESCEND
TO REACH (level)
BY (position)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1428

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-16 Instruction to

stop the climb at
the specified lev-
el and, once
reached, this lev-
el is to be main-
tained. The
specified level
will be below the
previously as-
signed level.
This instruction
should only be
issued when the
controller can
confirm that the
previously as-
signed level has
not yet been
reached.

STOP CLIMB
AT (level single)

W/U

UM169 ‘STOP
CLIMB AT (alti-
tude)’
NOTE: R response
attribute.

N/A

LVLU-17 Instruction to

stop the descent
at the specified
level and, once
reached, this lev-
el is to be main-
tained. The
specified level
will be above the
previously as-
signed level.
This instruction
should only be
issued when the
controller can
confirm that the
previously as-
signed level has

STOP DE-
SCENT AT (lev-
el single)

W/U

UM169 ‘STOP DE-
SCENT AT (alti-
tude)’
NOTE: R response
attribute.

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1429

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-18 Instruction to

climb at the
specified rate or
greater.

CLIMB AT (verti-
cal rate) OR
GREATER

W/U

UM171 CLIMB AT
(vertical rate) MINI-
MUM

LVLU-19 Instruction to

climb at the
specified rate or
less.

CLIMB AT (verti-
cal rate) OR
LESS

W/U

UM172 CLIMB AT
(vertical rate) MAX-
IMUM

LVLU-20 Instruction to de-

scent at the
specified rate or
greater.

DESCEND AT
(vertical rate)
OR GREATER

W/U

UM173 DESCEND
AT (vertical rate)
MINIMUM

LVLU-21 Instruction to de-

scent at the
specified rate or
less.

DESCEND AT
(vertical rate)
OR LESS

W/U

UM174 DESCEND
AT (vertical rate)
MAXIMUM

LVLU-22 Notification that

a clearance may
be issued for the
aircraft to com-
mence a climb to
the specified lev-
el at the speci-
fied number of
minutes after de-
parture.

EXPECT (level
single) (number
of minutes) AF-
TER DEPAR-
TURE

UM169 ‘EXPECT
(level single) (num-
ber of minutes) AF-
TER DEPAR-
TURE’

N/A

LVLU-23 Instruction to re-

port upon leav-
ing the specified
level.

REPORT LEAV-
ING (level sin-
gle)

W/U

UM128 REPORT
LEAVING (altitude)
NOTE: R response
attribute.

N/A

LVLU-24 Instruction to re-

port upon main-
taining the speci-
fied level.

REPORT MAIN-
TAINING (level
single)

W/U

UM129 REPORT
LEVEL (altitude)
NOTE: R response
attribute.

N/A

LVLU-25 Instruction to re-

port the present
level.

REPORT
PRESENT LEV-
EL

N/A
NOTE: Refer to A.
6

UM133 REPORT
PRESENT LEVEL

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1430

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-26 Instruction to re-

port upon reach-
ing the specified
vertical range.

REPORT
REACHING
BLOCK (level
single) TO (level
single)

W/U

UM180 REACH-
ING BLOCK (alti-
tude) TO (altitude)
NOTE: R response
attribute.

N/A

LVLU-27 Request to con-

firm the assigned
level.

CONFIRM AS-
SIGNED LEVEL

UM135 CONFIRM
ASSIGNED ALTI-
TUDE
NOTE: NE re-
sponse attribute.

N/A

LVLU-28 Request to pro-

vide the prefer-
red level.

ADVISE PRE-
FERRED LEV-
EL

UM169 ‘ADVISE
PREFERRED
LEVEL’
NOTE: R response
attribute.

UM231 STATE
PREFERRED LEV-
EL

LVLU-29 Request to pro-

vide the prefer-
red time and/or
position to com-
mence descent
to the aerodrome
of intended arriv-
al.

ADVISE TOP
OF DESCENT

UM169 ‘ADVISE
TOP OF DE-
SCENT’
NOTE: R response
attribute.

UM232 STATE
TOP OF DESCENT

LVLU-30 Request for the

earliest time or
position when
the specified lev-
el can be accep-
ted.

WHEN CAN
YOU ACCEPT
(level single)

UM148 WHEN
CAN YOU AC-
CEPT (altitude)
NOTE: NE re-
sponse attribute.

UM148 WHEN
CAN YOU AC-
CEPT (level)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1431

DATA LINK OPERATIONS

Level uplink message elements (LVLU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLU-31 Request to indi-

cate whether or
not the specified
level can be ac-
cepted at the
specified posi-
tion.

CAN YOU AC-
CEPT (level sin-
gle) AT (posi-
tion)

A/N

UM149 CAN YOU
ACCEPT (altitude)
AT (position)

N/A

LVLU-32 Request to indi-

cate whether or
not the specified
level can be ac-
cepted at the
specified time.

CAN YOU AC-
CEPT (level sin-
gle) AT TIME
(time)

A/N

UM150 CAN YOU
ACCEPT (altitude)
AT (time)

N/A

Level downlink message elements (LVLD)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message
element
identifier

Message ele-
ment intended
use

Format for
message ele-
ment display

Resp. FANS 1/A

ATN B1

LVLD-1

Request to fly at
the specified lev-
el or vertical
range.

REQUEST (lev-
el)

DM6 REQUEST
(altitude)
NOTE: Used for a
single level.

DM6 REQUEST
(level)

DM7 REQUEST
BLOCK (altitude)
TO (altitude)
NOTE: Used for a
vertical range.

LVLD-2

Request for a
climb to the
specified level or
vertical range.

REQUEST
CLIMB TO (lev-
el)

DM6 REQUEST
(level)
NOTE: Use of DM7
REQUEST BLOCK
(altitude) TO (alti-
tude) to request to
climb at a vertical
range.

DM9 REQUEST
CLIMB TO (level)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1432

DATA LINK OPERATIONS

Level downlink message elements (LVLD) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLD-3

Request for a
descent to the
specified level or
vertical range.

REQUEST DE-
SCENT TO (lev-
el)

DM10 REQUEST
DESCENT TO (al-
titude)
NOTE: Use of DM7
REQUEST BLOCK
(altitude) TO (alti-
tude) to request to
descend at a verti-
cal range.

DM10 REQUEST
DESCENT TO (lev-
el)

LVLD-4

Request for a
climb/descent to
the specified lev-
el or vertical
range to com-
mence at the
specified posi-
tion.

AT (position)
REQUEST (lev-
el)

DM11 AT (position)
REQUEST CLIMB
TO (altitude)
NOTE: A vertical
range cannot be
requested.

N/A

DM12 AT (position)
REQUEST DE-
SCENT TO (alti-
tude)
NOTE: A vertical
range cannot be
requested.

LVLD-5

Request for a
climb/descent to
the specified lev-
el or vertical
range to com-
mence at the
specified time.

AT TIME (time)
REQUEST (lev-
el)

DM13 AT TIME
(time) REQUEST
CLIMB TO (alti-
tude)
NOTE: A vertical
range cannot be
requested.

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1433

DATA LINK OPERATIONS

Level downlink message elements (LVLD) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

DM14 AT TIME
(time) REQUEST
DESCENT TO (al-
titude)
NOTE: A vertical
range cannot be
requested.

LVLD-6

Request for the
earliest time or
position that a
descent can be
expected.

WHEN CAN WE
EXPECT LOW-
ER LEVEL

DM52 WHEN CAN
WE EXPECT
LOWER ALTI-
TUDE

N/A

LVLD-7

Request for the
earliest time or
position that a
climb can be ex-
pected.

WHEN CAN WE
EXPECT HIGH-
ER LEVEL

DM53 WHEN CAN
WE EXPECT
HIGHER ALTI-
TUDE

N/A

LVLD-8

Report indicating
leaving the
specified level.

LEAVING (level
single)

DM28 LEAVING
(altitude)

N/A

LVLD-9

Report indicating
that the specified
level is being
maintained.

MAINTAINING
(level single)

DM37 LEVEL (alti-
tude)

N/A

LVLD-10 Report indicating

reaching the
specified vertical
range.

REACHING
BLOCK (level
single) TO (level
single)

DM76 REACHING
BLOCK (altitude)
TO (altitude)

N/A

LVLD-11 Confirmation that

the assigned lev-
el or vertical
range is the
specified level or
vertical range.

ASSIGNED
LEVEL (level)

DM38 ASSIGNED
ALTITUDE (alti-
tude)
NOTE: Used for a
single level.

DM38 ASSIGNED
LEVEL (level)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1434

DATA LINK OPERATIONS

Level downlink message elements (LVLD) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

DM77 ASSIGNED
BLOCK (altitude)
TO (altitude)
NOTE: Used for a
vertical range.

LVLD-12 Report indicating

that the aircraft's
preferred level is
the specified lev-
el.

PREFERRED
LEVEL (level
single)

DM67 ‘PREFER-
RED LEVEL (alti-
tude)’
NOTE 1: Re-
sponse to free text
UM169 ‘ADVISE
PREFERRED
LEVEL’.
NOTE 2: When
pre-formatting of
the downlink mes-
sage is not availa-
ble, the flight crew
can shorten to:
FL(altitude).

DM106 PREFER-
RED LEVEL (level)
NOTE: A vertical
range may be pro-
vided.

LVLD-13 Report indicating

climbing to the
specified level.

CLIMBING TO
(level single)

DM29 CLIMBING
TO (altitude)

N/A

LVLD-14 Report indicating

descent to the
specified level.

DESCENDING
TO (level single)

DM30 DESCEND-
ING TO (altitude)
NOTE: N alert at-
tribute.

N/A

DM61 DESCEND-
ING TO (altitude)
NOTE: Urgent alert
attribute.

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1435

DATA LINK OPERATIONS

Level downlink message elements (LVLD) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

LVLD-15 Indication that

the specified lev-
el can be accep-
ted at the speci-
fied time.

WE CAN AC-
CEPT (level sin-
gle) AT TIME
(time)

DM67 ‘WE CAN
ACCEPT (altitude)
AT TIME (time)’

DM81 WE CAN
ACCEPT (level) AT
(time)
NOTE: A vertical
range may be pro-
vided.

LVLD-16 Indication that

the specified lev-
el can be accep-
ted at the speci-
fied position.

WE CAN AC-
CEPT (level sin-
gle) AT (posi-
tion)

DM67 ‘WE CAN
ACCEPT (altitude)
AT (position)’

N/A

LVLD-17 Indication that

the specified lev-
el cannot be ac-
cepted.

WE CANNOT
ACCEPT (level
single)

DM67. ‘WE CAN-
NOT ACCEPT (al-
titude)’

DM82 WE CAN-
NOT ACCEPT (lev-
el)
NOTE: A vertical
range may be pro-
vided.

LVLD-18 Notification of

the preferred
time and position
to commence
descent for ap-
proach.

TOP OF DE-
SCENT (posi-
tion) TIME (time)

DM67 ‘TOP OF
DESCENT (time)’
NOTE: When pre-
formatting of the
downlink message
is not available, the
flight crew can
shorten to: TOD
(time).

DM109 TOP OF
DESCENT (time)

LVLD-19 Notification of

the present level.

Present level
(single level)

N/A
NOTE: Refer to A.
6

DM32 PRESENT
LEVEL (altitude)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1436

DATA LINK OPERATIONS

Crossing constraint message elements

Crossing constraints (CSTU)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

Message
element
identifier

Message ele-
ment intended
use

Format for
message ele-
ment display

Resp. FANS 1/A

ATN B1

CSTU-1

Instruction that
the specified po-
sition is to be
crossed at the
specified level or
within the speci-
fied vertical
range.

CROSS (posi-
tion) AT (level)

W/U

UM46 CROSS
(position) AT (alti-
tude)
NOTE: Used for a
single level.

UM46 CROSS (po-
sition) AT (level)

UM50 CROSS
(position) BE-
TWEEN (altitude)
AND (altitude)
NOTE: Used for a
vertical range.

UM49 CROSS
(position) AT AND
MAINTAIN (alti-
tude)
NOTE 1: A vertical
range cannot be
provided.
NOTE 2: This
message element
is equivalent to
CSTU-1 plus
LVLU-5 in Doc
4444.

N/A

CSTU-2

Instruction that
the specified po-
sition is to be
crossed at or
above the speci-
fied level.

CROSS (posi-
tion) AT OR
ABOVE (level
single)

W/U

UM47 CROSS
(position) AT OR
ABOVE (altitude)

UM47 CROSS (po-
sition) AT OR
ABOVE (level)

A.4.4

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1437

DATA LINK OPERATIONS

Crossing constraints (CSTU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

CSTU-3

Instruction that
the specified po-
sition is to be
crossed at or be-
low the specified
level.

CROSS (posi-
tion) AT OR BE-
LOW (level sin-
gle)

W/U

UM48 CROSS
(position) AT OR
BELOW (altitude)

UM48 CROSS (po-
sition) AT OR BE-
LOW (level)

CSTU-4

Instruction that
the specified po-
sition is to be
crossed at the
specified time.

CROSS (posi-
tion) AT TIME
(time)

W/U

UM51 CROSS
(position) AT (time)

UM51 CROSS (po-
sition) AT (time)

CSTU-5

Instruction that
the specified po-
sition is to be
crossed before
the specified
time.

CROSS (posi-
tion) BEFORE
TIME (time)

W/U

UM52 CROSS
(position) AT OR
BEFORE (time)

UM52 CROSS (po-
sition) AT OR BE-
FORE (time)

CSTU-6

Instruction that
the specified po-
sition is to be
crossed after the
specified time.

CROSS (posi-
tion) AFTER
TIME (time)

W/U

UM53 CROSS
(position) AT OR
AFTER (time)

UM53 CROSS (po-
sition) AT OR AF-
TER (time)

CSTU-7

Instruction that
the specified po-
sition is to be
crossed between
the specified
times.

CROSS (posi-
tion) BETWEEN
TIME (time)
AND TIME
(time)

W/U

UM54 CROSS
(position) BE-
TWEEN (time)
AND (time)

UM54 CROSS (po-
sition) BETWEEN
(time) AND (time)

CSTU-8

Instruction that
the specified po-
sition is to be
crossed at the
specified times.

CROSS (posi-
tion) AT (speed)

W/U

UM55 CROSS
(position) AT
(speed)

UM55 CROSS (po-
sition) AT (speed)

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1438

DATA LINK OPERATIONS

Crossing constraints (CSTU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

CSTU-9

Instruction that
the specified po-
sition is to be
crossed at or
less than the
specified times.

CROSS (posi-
tion) AT (speed)
OR LESS

W/U

UM56 CROSS
(position) AT OR
LESS THAN
(speed)

N/A

CSTU-10 Instruction that

the specified po-
sition is to be
crossed at or
greater than the
specified times.

CROSS (posi-
tion) AT (speed)
OR GREATER

W/U

UM57 CROSS
(position) AT OR
GREATER THAN
(speed)

N/A

CSTU-11 Instruction that

the specified po-
sition is to be
crossed at the
specified time
and at the level
or within the ver-
tical range as
specified.

CROSS (posi-
tion) AT TIME
(time) AT (level)

W/U

UM58 CROSS
(position) AT (time)
AT (altitude)
NOTE: A vertical
range cannot be
provided.

N/A

UM62 AT (time)
CROSS (position)
AT AND MAIN-
TAIN (altitude)
NOTE 1: A vertical
range cannot be
provided.
NOTE 2: This
message element
is equivalent to
CSTU-11 plus
LVLU-5 in Doc
4444.

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1439

DATA LINK OPERATIONS

Crossing constraints (CSTU) (continued)

Operational definition in PANS-ATM (Doc 4444)

CPDLC message sets

CSTU-12 Instruction that

the specified po-
sition is to be
crossed before
the specified
time and at the
level or within
the vertical
range as speci-
fied.

CROSS (posi-
tion) BEFORE
TIME (time) AT
(level)

W/U

UM59 CROSS
(position) AT OR
BEFORE (time) AT
(altitude)
NOTE: A vertical
range cannot be
provided.

N/A

CSTU-13 Instruction that

the specified po-
sition is to be
crossed after the
specified time
and at the level
or within the ver-
tical range as
specified.

CROSS (posi-
tion) AFTER
TIME (time) AT
(level)

W/U

UM60 CROSS
(position) AT OR
AFTER (time) AT
(altitude)
NOTE: A vertical
range cannot be
provided.

N/A

CONTROLLER PILOT DATA LINK COMMUNICATION

(CPDLC)

1440

DATA LINK OPERATIONS

JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21) - page 45