Aviation business leaders went to Brussels this week to discuss the consequences of Brexit for European aviation.
When the UK exits Europe in March 2019 it will also leave Open Skies unless some kind of agreement is signed before then. The challenge for carriers — as expressed most vociferously this week by Ryanair CEO Michael O'Leary — is that their timelines mean that they have to make decisions quite soon as air tickets go on sale from a year before date of travel.
In other words the post-Brexit flight schedules need to be posted in nine months' time and that means there's not a lot of time for decision-making, especially if you're an Irish company with a very large part of your operation in the UK.
Open Skies allows the airlines of one EU country to fly to another without the restrictions and permissions that a non-EU carrier might face. It's what's enabled both Ryanair and easyJet to expand so aggressively in the last 20 years.
Open Skies also enables any US carrier to fly to anywhere in Europe and vice versa as Norwegian's recent expansion in routes to the States demonstrates.
Norwegian's long-haul expansion is not, as you might expect from a 'low-cost', just about Florida holiday traffic. From London the airline also flies to Singapore and the US business destinations of Boston, Denver, Los Angeles, New York (JFK and Newark), Oakland, Providence and Seattle.
The "low cost" label is not deterring business traffic. Norwegian's premium product has everything a business traveller might want — lounge access, fast track, 46-inch seat pitch, at seat power points plus a frequent flyer programme. More importantly its destinations, especially Oakland and Seattle, are where many start-up businesses and their entrepreneurs want to travel.
And the hurdles to expansion are tumbling.
This week the last legal barrier to the airline's plans for services from Europe to the States was removed when US courts judged that airline unions had failed to prove that US Department of Transport's approval of Norwegian's route plans would hurt the working conditions of US pilots and cabin crew.
Europe is a critical ingredient in Norwegian's plans. The carrier's long-haul operation is managed via a subsidiary based in Dublin and therefore governed by EU treaties, which Norway is not. It is entitled to fly anywhere in the States because of the EU Open Skies agreement.
At a time when the UK is in the process of exiting it, the EU's importance to airlines cannot be underestimated. easyJet has operations in a number of European destinations but it will soon need an AOC (air operator certificate) from a European country in order to keep flying there seamlessly. Should easyJet ever wish to launch a long-haul operation it would have to base that operation in a European country to qualify for Open Skies just like IAG, parent of British Airways, which is a Spanish company.
It is of course possible to fly into Europe without being in Open Skies but it is subject to hurdles and not the same nimble decision. By having an Irish operation Norwegian is able quickly to launch routes that it thinks match the growth in demand among its target market.
Whether Michael O'Leary will remain able to be nimble with Ryanair's route network after Brexit remains to be seen.