Over 40 passenger airlines operate between the US and Europe. Using Cirium Diio data to examine every planned flight from April to December shows over 500 nonstop routes. Yet, five airlines—Air Tahiti Nui, Hainan Airlines, HiSky, Iberojet, and Singapore Airlines—have just one route in this most important of transatlantic markets, which had 77.75 million passengers last year. Things have changed dramatically in the past year.