World's biggest airline 2021: US airline reclaims title as world’s largest carrier

American Airlines has taken the pandemic as an opportunity to reemerge as the world's largest airline, a title it has traded back and forth with competitors during the last few years as Delta and United expanded their networks. But American Airlines has pulled ahead of rival Delta and is reestablishing routes and reconnecting with passengers to coincide with the uptick in summer travel. Based on flights scheduled, seat counts and how many passenger miles it has planned, American has been the biggest carrier in the world since April, according to airline schedule tracker Diio by Cirium. In fact, American's June schedule is about 21% bigger than Delta, its next largest rival. "American has been aggressive," said John Grant, the UK-based chief analyst for aviation data firm OAG. "You are very lucky in the United States to have a large domestic market." A handful of global rivals have traded the title of the world's largest airline during the COVID-19 pandemic as the ongoing outbreak upended the aviation world. At different times over the last 15 months, Qatar Airways, China Southern and Southwest have scheduled the most flights and passenger kilometres.<br/>