I visited Montréal–Pierre Elliott Trudeau International Airport (YUL) in August for a day before I fly out on Royal Air Maroc B747. I have a 100% sunny and cloud free late summer day in Montreal and it was perfect for photos.
There are some very decent spots in YUL in the afternoon that only require a small lens (up to 135mm) for every traffic taxi past you. For more spotting information, you can visit spotter wiki website.
The traffic is much heavier in the afternoon hours with no less than 30 long haul European arrivals and departures. Almost every major European and Canadian airlines is represented in Montreal. Montreal is an interesting place seeing many North African airlines such as Royal Air Maroc, Air Algerie, Tunisair sent their long haul planes there. The Swiss B777-300/ER is also a highlight for me.
Below are what I've caught on my camera during my spotting in the fine afternoon.