4/20/23
AIM
TBL 5
−
3
−
8
Voice Communications Uplink Message Elements (COMU)
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
UM117 CONTACT
(ICAO unit name)
(frequency)
UM117
CONTACT
(unit
name) (frequency)
W/U
COMU
−
1
Instruction to
establish voice
contact with the
specified ATS unit
on the specified
frequency.
CONTACT
(unit
name) (frequency)
UM120 MONITOR
(ICAO unit name)
(frequency)
UM120
MONITOR (
unit
name) (frequency)
W/U
COMU
−
5
Instruction to
monitor the
specified ATS unit
on the specified
frequency. The
flight crew is not
required to
establish voice
contact on the
frequency.
MONITOR
(unit
name) (frequency)
TBL 5
−
3
−
9
Voice Communications Downlink Message Elements (COMD)
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
DM20 REQUEST
VOICE CONTACT
Note
−
Used when a
frequency is not
required.
N/A
Y
COMD
−
1
Request for voice
contact on the
specified frequency.
REQUEST
VOICE
CONTACT
(frequency)
TBL 5
−
3
−
10
Emergency/Urgency Uplink Message Elements (EMGU)
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
Used in combination with
LVLU
−
6 and LVLU
−
9,
which is implemented in
FANS 1/A as:
UM38 IMMEDIATELY
CLIMB TO (
altitude
)
UM39 IMMEDIATELY
DESCEND TO (
altitude
)
N/A
N
EMGU
−
2
Instruction to
immediately
comply with the
associated
instruction to avoid
imminent situation.
Immediately
En Route Procedures
5
−
3
−
7