Taxi authorization and ground communication
Clearance required:
- Controlled airport: no movement on manoeuvring surfaces without clearance, even to reposition an aircraft not about to fly. Tell tower by radio, telephone, or other means (TP 1102, Manoeuvring Surfaces).
- Contact ground control before leaving apron and before entering manoeuvring area (RAC 1.2.4).
Who to call, and when:
- Ground control: request taxi authorization. No flight plan filed: state nature of flight on initial contact, e.g. "local VFR" or "proceeding VFR to (destination)" (RAC 4.2.5).
- Under tower control: keep listening watch on tower frequency. Taxi requests go to ground control, whenever possible (RAC 4.1).
What a taxi authorization covers (RAC 4.2.5 unless noted):
- Clears TO departure runway, never ONTO an active runway.
- Entering active runway, heading to or from it: always needs own authorization.
- Normal: to taxi-holding position for assigned runway.
- Any OTHER runway crossed en route: own instruction to cross or hold short. No instruction: hold short and request one.
- Push-back/power-back: tower never clears it, as controllers can't see every obstruction. Pilot ensures it is safe (RAC 4.2.4).
Oblique angle intersections onto an active runway:
| Who | Aerodrome | Rule | Ref |
|---|---|---|---|
| Controllers | - | Do not permit if departure threshold and final approach not visible from there | RAC 4.2.5.1 |
| Pilots | Uncontrolled | Encouraged to avoid oblique intersections that hide runway threshold or final approach | RAC 4.2.5.2 |
| Pilots | Controlled | Encouraged to avoid requesting them, except when tower controllers can permit it | RAC 4.2.5.2 |
- Controllers' exceptions: no other route without crossing or backtracking an active runway; non-routine situation (MEDEVAC, closed taxiway, disabled aircraft or vehicle) (RAC 4.2.5.1).
Phraseology while taxiing:
LINE UP AND WAIT: line-up point not threshold: controller names the intersection or taxiway. More than one entry point in use: controller also specifies which (RAC 4.2.5).- Progressive taxi: precise, step-by-step taxi instructions for a pilot unfamiliar with the aerodrome, or given in stages along the route (GEN 5.1).
| Instruction | Readback |
|---|---|
HOLD SHORT (runway or taxiway), HOLD, REQUEST YOU HOLD SHORT, REQUEST YOU HOLD |
Must read back |
| Ordinary taxi instructions | Acknowledgment only (RAC 4.2.5) |
| Entering, crossing, backtracking, or lining up on a runway | Read back as good practice (RAC 4.2.5) |
"Holding short" as a location only during frequency handoff, e.g. CONTACT TOWER HOLDING SHORT |
None: not a HOLD SHORT instruction |
- Must read back: ATC asks for one if not given.
- Read back hold point plus call sign, e.g.
HOLD SHORT OF (runway number)(PSTAR 3.14). - NAV CANADA VFR Phraseology also shows
HOLDING SHORT (runway number)(RAC 4.2.5, Hold Short).
- Read back hold point plus call sign, e.g.
Trap: taxi authorization to the runway does not clear you across every runway on the way; each crossing needs its own instruction, and no instruction means hold short and ask.
References
- TC AIM RAC 1.2.4
- TC AIM RAC 4.1
- TC AIM RAC 4.2.4
- TC AIM RAC 4.2.5
- TC AIM RAC 4.2.5.1
- TC AIM RAC 4.2.5.2
- TC AIM GEN 5.1
- TP 1102 Airport Operations: Manoeuvring Surfaces
- TP 1102 Taxiing
- TP 1102 Radio Communication: Ground Control
- NAV CANADA VFR Phraseology, Hold Short
- PSTAR 3.14