AIM

8/15/19

5

−

3

−

8

En Route Procedures

TBL 5

−

3

−

11

Emergency/Urgency Downlink Message Elements (EMGD)

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

DM55 PAN PAN PAN

Note  

−

 N response at-

tribute

N/A

Y

EMGD

−

1

Indication of an ur-
gent situation.

PAN PAN PAN

DM56 MAYDAY
MAYDAY MAYDAY

Note  

−

 N response at-

tribute

N/A

Y

EMGD

−

2

Indication of an
emergency  situa-
tion.

MAYDAY 
MAYDAY 
MAYDAY

DM57 (

remaining fu-

el

) OF FUEL RE-

MAINING AND 
(

remaining souls

)

SOULS ON BOARD

Note  

−

 N response at-

tribute

N/A

Y

EMGD

−

3

Report indicating
fuel  remaining
(time) and number
of persons on board.

(remaining fuel)

ENDURANCE
AND 

(persons on

board)

 PERSONS

ON BOARD

DM58 CANCEL
EMERGENCY 

Note  

−

 N response at-

tribute

N/A

Y

EMGD

−

4

Indication that the
emergency situation
is canceled.

CANCEL 
EMERGENCY

TBL 5

−

3

−

12

Standard Response Uplink Message Elements (RSPU)

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

UM0 UNABLE

UM0 UNABLE

N

RSPU

−

1

Indication that the
message cannot be
complied with.

UNABLE

UM1 STANDBY

UM1 STANDBY

N

RSPU

−

2

Indication that the
message will be re-
sponded to shortly.

STANDBY

UM3 ROGER

UM3 ROGER

N

RSPU

−

4

Indication that the
message is re-
ceived.

ROGER