There have been plenty of low cost carriers on the Transatlantic before. Affinity charters. Laker. PeoplExpress. And more. None of these have succeeded long term. They may get loads in the summer but just do not get the revenue to sustain a daily operation during the winter. They do not have the business contacts, corporate agreements, or the premium traffic. They are also pretty light on freight loads. The economy fares charged nowadays are difficult to beat by a significant margin. In more recent times, US travellers in particular seem quite averse to travelling other than with their favourite network carrier with its frequent flyer miles. Virgin only managed to scrape through by changing pretty rapidly from an LCC to a mainstream carrier.