AIM

8/15/19

5

−

3

−

4

En Route Procedures

CPDLC Message Sets

Operational Definition in PANS

−

ATM (Doc 4444)

FANS 1/A

ATN B1

Response

Message 
Element 

Identifier

Message Element

Intended Use

Format for 

Message Element

Display

UM23 DESCEND TO
AND MAINTAIN 

(altitude)
Note 

−

 Used for a sin-

gle level

UM23 DESCEND
TO (

level

)

W/U

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

)

UM36 EXPEDITE
CLIMB TO  

(altitude)

Note 

−

 This message

element is equivalent
to SUPU

−

3 plus

LVLU

−

6 in Doc 4444.

N/A

W/U

LVLU

−

6

Instruction that a
climb to the speci-
fied level or verti-
cal range is to
commence and
once reached is to
be maintained.

CLIMB TO (

level

)

UM37 EXPEDITE
DESCEND TO 

(altitude)

N/A

W/U

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

)

UM38 IMMEDIATE-
LY CLIMB TO  

(altitude)
Note 

−

 This message

element is equivalent
to EMGU

−

2 plus

LVLU

−

6 in Doc 4444.

N/A

W/U

LVLU

−

6

Instruction that a
climb to the speci-
fied level or verti-
cal range is to
commence and
once reached is to
be maintained.

CLIMB TO (

level

)

UM39 IMMEDIATE-
LY DESCEND TO 

(altitude)
Note 

−

 This message

element is equivalent
to EMGU

−

2 plus

LVLU

−

9 in Doc 4444.

N/A

W/U

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

)

UM135 CONFIRM
ASSIGNED ALTI-
TUDE

Note 

−

 NE response

attribute

N/A

Y

LVLU

−

27

Request to confirm
the assigned level.

CONFIRM AS-
SIGNED LEVEL

UM177 AT PILOTS
DISCRETION

N/A

NE

See Note

Request to confirm
the assigned level.

NOTE

−

ICAO Document 10037, Global Operational Data Link (GOLD) Manual does not include this in its tables.