EMMA2 CPDLC trials in Toulouse
Feb 14, 2008
Airbus, Thales Air Systems, DSNA
EMMA2 outcomes from Toulouse trials
CPDLC Ground Clearance Function Procedures
Page 2
Taxi out – global overview
Page 3
Taxi out – nominal case (1/4)
Pilot
ATCO
Voice contact on LFPG Delivery frequency
Notification (onboard initiated)
*
CPDLC establishment (ground initiated) *
Departure Clearance request
Departure Clearance * *
Pilot may append any
foreseen constraints (if
datalink: free
text?specific message?)
so that the EXPECT
then provided may
fulfil them
DELIVERY
Either through voice or
through datalink ? If
datalink, either CPDLC
or A623 ?
Only one
CPDLC
connection is
envisioned for
ground
operations
(TBC).
Ground
system will be
in charge to
propose the
messages to
the relevant
control
position.
EXPECT ROUTING TO HOLDING POINT Z8 RWY 27R VIA TWY
G N BD13 D Y11 RWY 27L K8 Z8 *
EXPECT
computed
by ground
system sent
in response
to
Departure
Cl. Request
(controller
may have to
validate it)
ROGER
CONTACT LFPG GND 121.800
WILCO
Page 4
Taxi out – nominal case (2/4)
Pilot
ATCO
Voice : Ground 121.800 , DLH123
Voice
phraseology
is only
provided as
an example
Voice : DLH123, proceed by datalink *
Voice : Proceeding by datalink , DLH123
STAND D8 + REQUEST START-UP CLEARANCE + REQUEST
PUSHBACK CLEARANCE *
GROUND #1
Start-up and pushback
requests may be sent
separately with or
without the current
position.
START-UP APPROVED & PUSHBACK APPROVED *
Start-up and
pushback
clearances are
sent separately
if requests had
been sent
separately
WILCO
Page 5
Taxi out – nominal case (3/4)
ATCO
Pilot
REQUEST TAXI
WILCO
Transfer to Ground#2
frequency when near to
N/NA2
GROUND #1
TAXI TO INTERSECTION N/NA2 VIA TWY G N
CONTACT LFPG GND 121.600 *
WILCO
Voice
phraseology
is only
provided as
an example
Voice : Ground 121.600 , DLH123
Voice : DLH123, proceed by datalink *
Voice : Proceeding by datalink , DLH123
TAXI TO RWY 27R VIA TWY N BD13 D Y11 HOLD SHORT RWY
27L *
GROUND #2
The next taxi clearance
may be provided
without pilot request
Transfer to
Tower
frequency
when near to
RWY 27L.
Message
could either be
Monitor or
Contact
WILCO
MONITOR LFPG TWR 119.250 *
WILCO
Page 6
Taxi out – nominal case (4/4)
Pilot
Only voice read-back
required (no
acknowledgment of
the datalink
information)
ATCO
Voice: DLH123, cross runway 27 left and maintain holding point K8 +
datalink information confirming the cross clearance,
for
moving map display purpose (removal of stop bar)
and
Runway Incursions alerting capability *
Voice remains
for runway
clearances. The
means through
which the
datalink
information is
sent is TBD.
Voice: crossing runway 27 left and maintaining holding point K8,
DLH123 *
TAXI TO HOLDING POINT Z8 RWY 27R VIA TWY K8 Z8 *
TBC
according to
airport
configuration
(i.e. relevant
through
datalink or
voice?)
WILCO *
Voice: DLH123, line-up runway 27 left and wait
+ datalink information confirming the cross clearance,
for moving map display purpose (removal of stop bar)
and Runway Incursions alerting capability *
TOWER
Only voice read-back
required (no
acknowledgment of
the datalink
information)
Voice remains
for runway
clearances. The
means through
which the
datalink
information is
sent is TBD.
Voice: lining up runway 27 left and waiting, DLH123
Only voice read-back
required (no
acknowledgment of
the datalink
information)
Voice: DLH123, cleared for take-off runway 27 left wind 280 degrees
10 knots + datalink information confirming the take-off clearance,
for moving map display purpose *
Voice: cleared for take-off runway 27 left, DLH 123 *
Page 7
Taxi in – global overview
Page 8
Taxi in - Nominal case with APP, TWR & GND equipped with CPDLC (1/3)
Pilot
Either through voice or
through datalink ?
ATCO
CPLDC already established with APP
ATIS request
ATIS *
RWY exit *
EXPECT ROUTING TO STAND D8 VIA TWY V1 S2 RWY 26R S2
W2 N E GE2 G *
ROGER
EN ROUTE-APPROACH
RWY exit data
provided from ATC via
TBD
EXPECT
computed
from RWY
exit, if
available,
otherwise
“standard”
routing (TBC)
ground forwarding between Approach and Ground *
Ground
forwarding
may enable
the Approach
to exchange,
with the pilot,
data related to
ground
operations
(e.g. taxi route
information)
Transfer to Tower
frequency
CONTACT LFPG TWR 119.25 *
Only one CPDLC connection
is envisioned for ground
operations (TBC). Ground
system will be in charge to
propose the message to the
relevant control position.
WILCO
Transfer of CPDLC connexion between APP and ground system *
(seamless transfer for the crew – no “manual” notification required)
Page 9
Taxi in - Nonimal case with APP, TWR & GND equipped with CPDLC (2/3)
Pilot
ATCO
Voice : Tower 119.25 , DLH123
Voice: DLH123, wind 270 12 knots,runway26 left cleared to land.
Report runway vacated or in case of missed approach.
Voice : Runway 26 left, cleared to land, DLH123
TOWER
Voice : Runway 26 left vacated on taxiway V1, DLH123
Voice: DLH123, hold short of runway 26 right on taxiway S2.
Voice : holding short of 26 right, on taxiway S2, DLH123
Only voice read-back
required (no
acknowledgment of
the datalink
information)
Voice remains
for runway
clearances. The
means through
which the
datalink
information is
sent is TBD.
Voice: DLH123, cross runway 26 right and maintain holding point S2
+ datalink information confirming the cross clearance for moving map
display purpose only *
Voice: crossing runway 26 right and maintaining holding point S2,
DLH123 *
Transfer to Ground
frequency
CONTACT LFPG GND 121.8
WILCO *
Page 10
Taxi in - Nonimal case with APP, TWR & GND equipped with CPDLC (3/3)
ATCO
Pilot
Voice : Ground 121.8 , DLH123
The taxi clearance
after landing may be
provided without pilot
request
Voice : Proceeding by datalink , DLH123
GROUND
Voice : DLH123, proceed by datalink *
TAXI TO STAND D8 VIA TWY S2 W2 N E GE2 G *
WILCO
Page 11
Voice
phraseology
is only
provided as
an example
Expect Routing information use
Page 12
EXPECT ROUTING use (1/2)
• Purpose: It intends to inform the flight crew of the taxi route or at least the final destination,
i.e. the take-off runway for taxi out and the stand/parking for taxi in, even if the controller
sending this information message is not in charge of the final destination
• Taxi out : 2 messages possible
• UL#243 : EXPECT ROUTING TO [airportElement] VIA [ •taxiRoute] [taxiRouteClearance]
Start of taxi
Entry in an area depending
on a different controller
Expected final
destination
 provides the expected taxi route to the final destination
• UL#254 : EXPECT ROUTING TO [airportElement] WITH PUSHBACK FACING
[direction]
only the final destination and optionally the pushback direction are known
Note: the airportElement and the taxiRoute elements are the information displayed on the DCDU and the
taxiRouteClearance element is dedicated to the graphical depiction on the moving map.
Page 13
EXPECT ROUTING use (2/2)
• Taxi out (cont.) :
• Information useful during flight preparation, i.e. at the same time departure clearance
is granted
Pilot
ATCO
Departure Clearance request
Departure Clearance
Either through voice or
through datalink ?
EXPECT ROUTING TO HOLDING POINT Z8 RWY 27R VIA TWY
G N BD13 D Y11 RWY 27L K8 Z8
ROGER
• Taxi in : only one message relevant
• UL#243 : EXPECT ROUTING TO [airportElement] VIA [taxiRoute]
[taxiRouteClearance] , same intent/features as for taxi out
• Information useful early during the approach phase (appropriate moment is TBD- not
worthy while a/c on ground)
Page 14
Taxi clearance use
Page 15
TAXI CLEARANCE use (UL#241) – 1 / 4
A / Case of runway crossing, final destination known
Start of taxi
HP of RWY to cross
1st message Taxi To
TAXI TO [airportElement]
VIA [taxiRoute]
Final destination
2nd message Taxi To
TAXI TO [airportElement]
VIA [taxiRoute]
HOLD SHORT OF [airportElement]
(the end of clearance point corresponds to a
holding point)
[taxiRouteClearance]
[taxiRouteClearance]
Note: the airportElement and the taxiRoute elements are the information displayed on the DCDU and the
taxiRouteClearance element is dedicated to the graphical depiction on the moving map..
Page 16
TAXI CLEARANCE use (UL#241) – 2 / 4
A / Case of runway crossing, final destination known
Pilot
ATCO
TAXI TO RWY 27R VIA TWY N BD13 D Y11 HOLD SHORT OF
RWY 27L
WILCO
Aircraft cleared to
cross RWY 27L
TAXI TO HOLDING POINT Z8 RWY 27R VIA TWY K8 Z8
WILCO
Note: the use of datalink taxi clearance after runway crossing is TBC according to airport configuration (i.e. relevant through datalink or voice? A
priori interviewed ground controllers mentioned they would aim at always updating their system even when few remaining taxi route but it should be
confirmed)
Page 17
TAXI CLEARANCE use (UL#241) – 3 / 4
B / Case of final destination unknown, ground control segmentation
Start of taxi
Final destination
Ground control limit point
1st message Taxi To
TAXI TO [airportElement]
VIA [taxiRoute]
[taxiRouteClearance]
2nd message Taxi To
TAXI TO [airportElement]
VIA [taxiRoute]
[taxiRouteClearance]
Note: the airportElement and the taxiRoute elements are the information displayed on the DCDU and the
taxiRouteClearance element is dedicated to the graphical depiction on the moving map.
Page 18
TAXI CLEARANCE use (UL#241) – 4 / 4
B / Case of final destination unknown, ground control segmentation
Pilot
ATCO
TAXI TO INTERSECTION N-NA2 VIA TWY G N
CONTACT LFPG GND 121.8
GROUND#1
WILCO
WILCO
Voice : DLH123, proceed by datalink
Voice : Proceeding by datalink , DLH123
GROUND#2
Voice : Ground 121.8 , DLH123
TAXI TO HOLDING POINT Y13 RWY 27L VIA N B BQ2 Y13
WILCO
Page 19
Revise taxi clearance use
Page 20
REVISE TAXI CLEARANCE use (UL#244) – 1 / 2
Start of taxi
1st message :
Current a/c position
End of taxi clearance point
TAXI TO [airportElement] VIA [taxiRoute] HOLD SHORT OF
[airportElement] [taxiRouteClearance]
End of revise taxi
Clearance point
2nd message :
REVISE TAXI TO [airportElement] VIA [taxiRoute] HOLD SHORT OF
[airportElement] [taxiRouteClearance]
Revision is sent from the current position of the aircraft (not from the deviating point)
The end of the revise taxi clearance point may be the same as the end of initial taxi clearance point
provided that a part of the taxiRoute is different.
Note: the airportElement and the taxiRoute elements are the information displayed on the DCDU and the
taxiRouteClearance element is dedicated to the graphical depiction on the moving map.
Page 21
REVISE TAXI CLEARANCE use (UL#244) – 2 / 2
Pilot
ATCO
TAXI TO HOLDING POINT Y13 RWY 27L VIA N B BQ2 Y13
WILCO
GROUND
Long Term
change in the
cleared taxi route
=> revision only
managed by
datalink
REVISE TAXI TO HOLDING POINT Y11 RWY 27L VIA B BD20
Y11
WILCO
Page 22
Mixed mode communication
Page 23
MIXED MODE COMMUNICATION (2/2)
•
Example :
ATCO
Pilot
TAXI TO HOLDING POINT Y11 RWY 27L VIA N BD13 D Y11
WILCO
Voice : Taxiing holding point Y11 runway 27 left via taxiway B BD20
Y11, DLH123
Near
intersection
N/B
GROUND
Voice : DLH123, disregard CPDLC TAXI message. Turn right on B. +
simultaneous sending of a datalink warning dedicated to the airport
moving map (e.g. TAXI CLEARANCE: CHANGE IN PROGRESS)
Voice phraseology
is TBC and the use
of a datalink
warning dedicated
to the airport
moving map is to
further studied
REVISE TAXI TO HOLDING POINT Y11 RWY 27L VIA B BD20
Y11
WILCO
Page 24
CPDLC Ground Clearance Messages
Recommendations
Page 25
How to read the message tables
• Caption
 UM
: Uplink Message
 DM
: Downlink Message
 In
[ ] : parameter
 In
italic : optional field
• Sorting into groups (to be normalized or not)
 Meaning
of colours used:
EMMA2 messages to be evaluated before normalisation of D-TAXI
EMMA2 messages to be modified for normalisation of D-TAXI
Messages recommended for normalisation of D-TAXI
EMMA2 messages not recommended for normalisation of D-TAXI
Page 26
UPLINKS – Existing messages
UM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
0
UNABLE
UNABLE
1
STANDBY
STANDBY
3
ROGER
ROGER
73
[departureClearance]
Modification of the format defined in
SARPs ATN (newUM73=UM288
envisioned by WG78 at 1st of march
09)
117
CONTACT [unitName]
[frequency]
CONTACT [unitName]
[frequency]
120
MONITOR [unitName]
[frequency]
MONITOR [unitName]
[frequency]
Justification
Basic PAM (Pilot Acknowledgement
Messages)
The introduction of DCL service through
CPDLC service should be further studied
ATC Communication Management
(ACM) for voice communication
transfer
158
ATIS [ATISCode]
ATIS [ATISCode]
Reminder of ATIS code number, to be
used in conjunction with start-up,
pushback, taxi, or take-off clearances.
199
Free text
Free text
Operational free text
Page 27
UPLINKS – Basics
UM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
239
[clearanceType] APPROVED
[airportLocation]
[clearanceType] APPROVED
[airportLocation] [time]
Justification
Can be used for pushback and start-up clearances.
The optional parameter [airportLocation] may include a
stand position or a pushback direction.
The time parameter is optional and could be appended
to provide further information
240
TAXI TO [airportElement]
VIA [taxiRoute]
HOLD SHORT OF
[airportElement]
Not recommended for
normalisation
If the parameter [taxiRouteClearance] is made
optional, this message becomes useless.
241
TAXI TO [airportElement]
VIA [taxiRoute]
HOLD SHORT OF
[airportElement]
[taxiRouteClearance]
TAXI TO [airportElement]
VIA [taxiRoute]
HOLD SHORT OF
[airportElement]
[taxiRouteClearance]
1) The parameter [taxiRouteClearance], containing the
data for graphical display, should be made optional, so
that it allows a flexible use with or without the graphical
data.
2) The parameter [taxiRouteClearance] should allow a
flexible definition of the taxi route to be displayed on a
moving map, with either a sequence of type Lat/Long,
or a sequence of type taxiway identifiers (still to be
defined according to airport data bases).
Page 28
UPLINKS – Clearance revisions
UM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
244
REVISE TAXI TO
[airportElement]
VIA [taxiRoute]
HOLD SHORT OF
[airportElement]
[taxiRouteClearance]
REVISE TAXI TO
[airportElement]
VIA [taxiRoute]
HOLD SHORT OF
[airportElement]
[taxiRouteClearance]
Same remarks as for UM#241 on the parameter
[taxiRouteClearance].
REVISE TAXI TO
[airportElement]
VIA [taxiRoute]
HOLD SHORT OF
[airportElement]
Not recommended for
normalisation
If the parameter [taxiRouteClearance] is made optional,
this message becomes useless.
253
Justification
This message should have a higher priority
characterization.
Page 29
UPLINKS – EXPECT ROUTING
UM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
243
EXPECT ROUTING TO
[airportElement]
VIA [taxiRoute]
[taxiRouteClearance]
EXPECT ROUTING TO
[airportElement]
VIA [taxiRoute]
[taxiRouteClearance]
Same remarks as for UM#241 on the parameter
[taxiRouteClearance].
254
EXPECT ROUTING TO
[airportElement]
WITH PUSHBACK FACING
[direction]
EXPECT ROUTING TO
[airportElement]
WITH PUSHBACK FACING
[direction]
This new message is a counterpart of UM243 with only
the destination, which is the most important parameter.
Justification
The part with the [direction] parameter is optional. If the
detailed taxiRoute is unknown, at least a provision of the
pushback direction is useful to pilots.
This message is not a key element of the message set
(optional).
The direction parameter needs to be more precise if
graphical.
Page 30
UPLINKS – Options
UM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
250
DUE TO [airportElement]
CONGESTION
Optional
DUE TO FLOW
REGULATION
Optional
251
Justification
To be used in conjunction with UM0 UNABLE.
Not very useful operationally.
The following messages answer a specific graphical need, but should not require an answer from pilots, and even should not
be presented as a textual CPDLC message.
UM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
Justification
This UM is meant for controllers to alert pilots that the
previous TAXI CPDLC clearances are invalidated
(superseded by voice for short term change).
258
TAXI CLEARANCE:
CHANGE IN PROGRESS
TAXI CLEARANCE :
CHANGE IN PROGRESS
This message is more dedicated to the map and may be
useless on DCDU. Further study should be performed to
determine if CPDLC is thus appropriate. No answer should
be required from pilots.
This message should have a higher priority characterization.
xxx
RESUME OWN TAXI
To be used following a use of voice (e.g. requiring the
a/c to stop) if the previous datalink taxi clearance is still
valid. No answer should be required from pilots.
Page 31
UPLINKS – Runway clearances
UM
#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
242
CROSS [runwayInformation]
CROSS [runwayInformation]
xxx
AND MAINTAIN
xxx
BACKTRACK [runwayinformation]
255
LINE-UP [runwayInformation]
LINE-UP [runwayInformation]
256
CLEARED FOR TAKE-OFF
[runwayInformation]
CLEARED FOR TAKE-OFF
[runwayInformation]
Justification
Further study should be performed on the
appropriateness of CPDLC runway clearances.
It is recommended to study a procedure where
runway clearances are provided through voice
and the associated datalink messages
(CPDLC?) would only be a graphical support.
These messages are a pre-requisite for an
onboard safety net against runway incursions.
Several combinations may be envisioned, eg.
BACKTRACK + LINE UP + AND MAINTAIN,
TAXI TO...VIA... + BACKTRACK, CROSS +
TAXI TO...
These messages answer a specific graphical need, but should not require an answer from pilots, and even should not be
presented as a textual CPDLC message.
Page 32
UPLINKS – Traffic management
UM#
257
xxx
In EMMA2 AIF Std2 trials
BEHIND
[aircraftFlightIdentification]
[aircraftType]
Recommendation for
normalisation of D-TAXI
BEHIND
[aircraftFlightIdentification]
[aircraftType]
Justification
Messages linked to traffic - should be further
evaluated, especially regarding the a/c identifier
issue.
[aircraftType] (ie A320, B777) is optional.
This message could be appended to
taxi/revision clearance or pushback approval.
GIVE WAY TO
[aircraftFlightIdentification]
[aircraftType]
Page 33
DOWNLINKS – Existing messages
D
M
#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
0
WILCO
WILCO
1
UNABLE
UNABLE
2
STANDBY
STANDBY
3
ROGER
ROGER
Justification
Basic PAM (Pilot Acknowledgement
Messages)
UNABLE is scarcely used operationally.
clearanceType = Start-up, Pushback, Taxi,
Departure.
25
[airportLocation] REQUEST
[clearanceType]
[airportLocation] REQUEST
[clearanceType]
66
DUE TO AIRCRAFT
PERFORMANCE
DUE TO AIRCRAFT
PERFORMANCE
67
Free Text
Free Text
Could possibly be used for Line-up, Take-off
Note: WG78 envisions to define a dedicated DM for
departure request (DM118 REQUEST DEPARTURE
CLEARANCE [departureClearanceRequestData]TBC)
Page 34
DOWNLINKS – EMMA Messages
DM#
In EMMA2 AIF Std2 trials
Recommendation for
normalisation of D-TAXI
114
[airportLocation]
[airportLocation]
115
DUE TO AIRCRAFT TYPE
DUE TO AIRCRAFT TYPE
Justification
[airportLocation] would be used optionally at StartUp or Push-Back in conjunction with DM#25.
The position reporting at parking is essential to
controllers.
For taxiway compatibility (weight, wing span)
Message to be further evaluated.
118
FOR [runwayInformation]
ABLE INTERSECTION
TAKE-OFF FROM
[intersection]
FOR [runwayInformation]
ABLE INTERSECTION TAKEOFF FROM [intersection]
To be used optionally in conjunction with DM25
REQUEST TAXI CLEARANCE, to request a taxi
for intersection take-off.
The message has two parts, which are optional:
FOR [runwayInformation], and ABLE
INTERSECTION TAKE-OFF FROM [intersection]
Page 35