Written with AI assistance and may contain mistakes. Verify against the official Transport Canada publications before relying on anything here.

Departure radio sequence at a controlled aerodrome

Fixed order, one job per unit. Wrong unit or skipped step breaks the order ATC expects.

Departing, in order:

#	Unit	When	Job	Cite
1	ATIS	If provided	First unit; listed in CFS	TP 1102, Radio Communication: ATIS
2	Clearance Delivery	If CFS requires	Primarily issues IFR clearances to aircraft on the ground	TP 1102, Radio Communication: Clearance Delivery
3	Ground	In sequence	Taxi clearance to and from active runway	TP 1102, Radio Communication: Ground Control
4	Tower	In sequence	Takeoff clearance	TP 1102, Take-off

Clearance Delivery:

Some airports: all departing aircraft must call after receiving ATIS.
Check in with aircraft type, registration, ATIS code letter.
CFS gives whether call required, and frequency (TP 1102, Radio Communication: Clearance Delivery).
IFR: call before requesting taxi authorization, normally no more than 5 minutes before engine start.
Several major aerodromes: VFR must also call before taxiing (TC AIM RAC 4.2.2).

Ground:

No ATIS: ground relays all pertinent info instead (TP 1102, Radio Communication: Ground Control).

Tower:

Even after takeoff clearance, ask for revised clearance if safer to wait or alter plan. Controller may not know all circumstances (TP 1102, Take-off).
After liftoff: stay on tower frequency and keep monitoring. Departure instructions can change any time until clear of control zone (unless told otherwise).
IFR traffic may work same zone on other frequencies. Keep sharp look-out despite tower/IFR coordination (TP 1102, Radio Communication: Tower Control Departing).

Trap: leaving tower frequency right after liftoff. Instructions can change until clear of the control zone.

PPL Tester