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

Aerodrome signs

Airside sign categories (AGA 5.8.1):

Category	Colours	Purpose / placement
Information	Black on yellow; location sign is yellow on black	Identify destination, location, frequency, routing
Mandatory instruction	White on red	Both sides of taxiway or runway unless physically impossible, then equivalent painted marking (AGA 5.8.3)

Information signs (AGA 5.8.2):

Sign	Colours	Identifies	Arrow
Location	Yellow on black	Taxiway aircraft is on or entering	Never
Direction	Black on yellow	Intersecting taxiway ahead	Always (angle of intercept)
Runway exit	Black on yellow	Taxiway exiting a runway	Always (exit angle)
Destination	Black on yellow	General guidance to airfield points, used sparingly	Always

Direction sign:
- Left of taxiway, before intersection, whenever practicable.
- With location sign: location centre, left-turn signs to its left, right-turn to its right.
- Simple "T" intersection exception: location sign opposite (top of the T), facing the taxiway.
- Also flags a through taxiway that changes heading more than 25° or changes designation.
Runway exit sign:
- Before the intersection, on exit side.
- Both sides where a taxiway crosses a runway.
- May be omitted where aircraft don't normally exit, or on a one-way taxiway.
Other information signs: stand ID, parking, frequency.
Locations other than runway ends: sign shows both runways' designators, location sign outboard beside the runway designator.

Mandatory instruction signs (AGA 5.8.3): mark points needing further ATC clearance to proceed.

Mark: runway designations, holding positions, NO-ENTRY areas, obstacle-free zones.
Area of compass unreliability: runway designation sign shows exact true azimuth, three digits.
CAT I/II/III holding position signs:
- Each side of taxiway, in line with CAT hold position marking.
- Inscribed with runway designator and CAT designation.
- Protect ILS critical area during IFR precision operations.
NO-ENTRY sign: at start and on both sides of prohibited area.

Night or low visibility (fibre-optic signs, AGA 5.8.4): only lit characters show.

Trap: location sign never has an arrow. Direction, runway exit, destination always do.

PPL Tester