Both TAP, Air Canada and Canadian Airlines had problems with their Canada to Portugal flights. TAP gave up in the mid-90s after losing lots of money on its BOS
routes which were mostly made up of low-yield VFR traffic. EWR
were kept because of New York's position as a business hub, but eventually JFK
was cut in 2002 and EWR
kept because not only is there a large Portuguese population in the area (also mostly from continental Portugal unlike Canada or New England), but it's close to Manhattan and offers good connections across North America. SATA International took over since most of the traffic was seasonal and going to the Azores. This means that SATA can fly charters to Oakland, Providence, Boston, Toronto, etc catering to large overseas Azorean communities during seasonal peaks.
1. The Portuguese communities in Toronto and Montreal are large, however with little business travel traffic between both countries, these are very low-yielding flights. Though they did have high load factors, they were notoriously unprofitable for TAP. I assume it must have been the case for CP
or else they wouldn't have axed Lisbon. This traffic is very unstable as it fluctuates with peaks during summer months and holidays making it perfect for charter carriers.
2. The majority of the Portuguese people living in Canada are from the Azores. This means that they have to take connecting flights from Lisbon anyway. Note no carrier flies scheduled flights from BOS
to Portugal and New England has a larger Portuguese (mostly Azorean) population than Canada.
3. Lisbon does not offer the connecting possibilities that LHR
or must hubs do in Europe. BA
, etc all have extensive networks from their hubs making connections to Eastern Europe, the Middle East, India, Africa all possible with one stop. This means these larger carriers are able to rely on more than O+D pax, something TAP cannot due since they do not fly anywhere in Asia or the Middle East. Air Canada too can only really connect pax from the rest of Canada and some cities in North America.
4. Lisbon suffers a great disadvantage geographically as a North American hub. Look at the great circle route, LHR
make a perfect hub for flying to other destinations in Europe or Asia. LIS
does not, however it does make a great hub for flying Europe to Brazil, hence TAP's building up of its Brazilian network.