EI Transatlantic routes
Of course there are enough aircraft to serve both LAX and SFO - it all depends on frequency of service but the down side is for example, the cost of 2 sets of check on desks, 2 baggage handling contracts etc.
Do you not think that if Cork-US was viable, United Continental would have tried it to EWR or Delta could have to JFK? As for Belfast, if United Continental is struggling, how could someone else coming it make a go of it?