I'm guessing that there are a couple of factors in play here: demand and frequency.
I don't see much demand between most hubs in the US and destinations in Quebec (outside of YUL
) or most places in the Maritimes, and at this point YUL
is still primarily a hub to Quebec and the Maritimes (though AC
's European route development may change this)
Further, most of the US destinations served from YUL
are close enough that an acceptable frequency is only achievable with regional operations (ie. NYC, WAS, PHL
Of those destinations that are far enough to get mainline service, the service is provided by AC
) or by multiple airlines to Florida (TS, WS
Interestingly, other than ORD
, none of the US hubs with regional service to YUL
have mainline service on an american carrier to YYZ
! So I'm guessing that the desire for more frequencies than are sustainable with mainline aircraft is the biggest reason that YUL
sees so little mainline from the US.