A massive winter storm that swept through 12 states in the United States left businesses in darkness and led to the cancellation of over 1,200 flights on Friday. The widespread power outages and the looming threat of a severe freeze over the weekend prompted airlines to take precautionary measures, resulting in 1,243 cancellations and 514 delays, according to flight-tracking website FlightAware.

Delta Air Lines acknowledged the operational challenges posed by the Midwest weather, stating, "We anticipate some operational challenges due to the weather in the Midwest today and potentially tomorrow, due to the wintry conditions in the region." The Federal Aviation Administration had issued a warning on Thursday, cautioning that clouds, snow, and strong winds could cause flight delays at certain airports. The impact of this winter weather on air travel has been substantial, living up to the earlier advisory. Among the airlines affected, United Airlines Holdings led the list of cancellations with 238 flights, followed by 215 flights by Southwest Airlines.

In response to the disruption, United Airlines has also cancelled some flights through Saturday as it awaits regulatory approvals to resume operating Boeing's 737 MAX 9 jets in the country. The FAA had initiated a formal investigation into the 737 MAX 9 after a cabin panel blew off an Alaska Airlines flight last week in mid-air, forcing an emergency landing. The situation has highlighted the significant challenges that the airline industry faces in the midst of severe weather conditions, and the impact it can have on air traffic across the country.