why don't I hear them tell aircraft to go to boston center? is that done by CPDLC
Moncton (and all Canadian ATC for that matter) use CPDLC for a lot of functions, most of the handoffs in this area (in high level airspace) are done using CPDLC, so you won't hear anything.
These are the supported CPDLC functions.
A4471/14 NOTAMR A2776/14
Q) CZQM/QCDXX/IV/NBO/E /000/999/4729N08055W999
A) CZQM
B) 1406091318
C) PERM
E) CZQM WEF 2014 APR 12 1300
CPDLC PHASE 1, 2, AND 3 FOR MONCTON ACC IMPLEMENTED WITHIN HIGH
LEVEL AIRSPACE FL290 AND ABOVE AS PER AIC 15/14.
ONLY THE FOLLOWING DOWNLINK MESSAGES WILL BE SUPPORTED BY MONCTON
ACC:
DM0 - WILCO
DM1 - UNABLE
DM2 - STANDBY
DM3 - ROGER
DM4 - AFFIRM
DM5 - NEGATIVE
DM6 - REQUEST (ALT)
DM9 - REQUEST CLIMB TO (ALT)
DM10 - REQUEST DESCENT TO (ALT)
DM18 - REQUEST (SPEED)
DM20 - REQUEST VOICE CONTACT
DM21 - REQUEST VOICE CONTACT (FREQ)
DM22 - REQUEST DIRECT TO (POS)
DM28 - LEAVING (ALT)
DM29 - CLIMBING TO (ALT)
DM30 - DESCENDING TO (ALT)
DM32 - PRESENT ALTITUDE (ALT)
DM34 - PRESENT SPEED (SPEED)
DM37 - LEVEL (ALT)
DM38 - ASSIGNED LEVEL (LEVEL)
DM39 - ASSIGNED SPEED (SPEED)
DM47 - SQUAWKING (CODE)
DM55 - PAN PAN PAN
DM56 - MAYDAY MAYDAY MAYDAY
DM57 - (FUEL) (FUEL2) FUEL REMAINING (SOULS) SOULS ON BOARD
DM58 - CANCEL EMERGENCY
DM60 - OFFSETTING (DOFF) (DIR) OF ROUTE
DM61 - DESCENDING TO (ALT)
DM62 - ERROR (ERROR INFORMATION)
DM63 - NOT CURRENT DATA AUTHORITY
DM64 - (ICAO FACILITY DESIGNATION)
DM65 - DUE WEATHER
DM66 - DUE AIRCRAFT PERFORMANCE
DM67 - FREE TEXT
DM80 - DEVIATING (DOFF) (DIR) OF ROUTE
ANY DOWNLINK MESSAGE OTHER THAN THE ABOVE WILL GENERATE A 'MESSAGE
NOT SUPPORTED BY THIS FACILITY' RESPONSE FROM THE GROUND SYSTEM.
I also heard the Moncton controller call a flight asking if they had just requested a specific speed via CPDLC. The flight answered "yes" and the controller kindly asked them to make those kinds of requests via voice and not to use CPDLC for that
Speed changes are supported so not sure why the controller would ask them not to use CPDLC ? Can you remember the approximate time so I can check the archive to get context ? Maybe he was talking about his speed pertaining to his oceanic clearance ?