Airlines of the EU are also allowed to fly between the US and non-EU countries that are part of the European Common Aviation Area, like Switzerland.
Nevertheless, expansion of transatlantic flights to or from Heathrow continue to be limited by lack of runway capacity (currently its two runways operate at over 98 percent capacity), government limits (especially when expansion plans to build a third runway and a sixth terminal were cancelled on 12 May 2010, by the new coalition government[6]), and the fact that many take-off slots are owned by incumbent airlines (IAG's airlines, including British Airways, Aer Lingus and Iberia, account for 54% of slots[7]).
[8] There have been a number of new entrants that have come into the market in recent years, who have adapted the model of the short-haul low-cost airlines to the transatlantic route.
Initially in 2007, Ryanair announced that it was planning to start a new airline (RyanAtlantic) that would operate long-haul flights between Europe and the United States but that project was cancelled.
However, in 2014 Norwegian Air Shuttle announced it would start low-cost flights to the US from the Republic of Ireland and later the UK, in part made possible by new wide-body and narrow-body aircraft with increased fuel efficiency and range.
[10][11] Eventually, after the European Commission said it would initiate arbitration procedures under the Agreement,[12] the US granted the Norwegian subsidiaries rights to fly to the US.
[15] Both the EU and the Secretary of State for Exiting the European Union, David Davis, have since confirmed it was likely the UK would leave the EU-US Open Skies Agreement.