Major US carriers stumbled through another money-losing quarter at the end of the 2021 but remain confident of a travel recovery later in 2022, based in part on hopes that Covid-19 will soon evolve into an ordinary and seasonal virus.Major US carriers stumbled through another money-losing quarter at the end of the 2021 but remain confident of a travel recovery later in 2022, based in part on hopes that Covid-19 will soon evolve into an ordinary and seasonal virus.