Spotting is allowed, even encouraged, at YYC
. The 'official' Edward H. LaBorde viewing area is to the W. of runway 34 threshold off McKnight Boulevard. You can't miss it, although it's only good for photography from about 2pm on.
There are two other spots, one at the 28 threshold off McCall Way which is difficult (but not impossible) for photos due to a double fence and is only good until about midday; the other round by the Viking hangar in McTavish court, E. of R34 and therefore excellent in the morning.
In addition you can park in the cargo near the fire station, although this is not a recognised spot and you could get moved on although it's never happened to me. This is about the only place for a southerly flow (16/10) that I know of and is far from satisfactory. Best to check the wind before setting out. Be prepared to see a lot
of Westjet 737s
There are probably other locations reachable on foot (looong walks) but I'm too lazy to have explored. You can get some limited shots from the sidewalk at each end of the terminal too.