A shortage of airline staff has forced thousands of flights to be delayed or cancelled in the United States.
Around 1,000 flights were cancelled by the afternoon on Tuesday and nearly 3,000 flights were delayed.
Alaska Airlines and SkyWest Airlines were hit particularly hard.
However, a looming change to COVID isolation rules may alleviate the pressure on airlines.
Americans who test positive but are asymptomatic now only have to quarantine for five days instead of 10.