- The July 4 holiday weekend has been struck by travel chaos.
- Almost 5,000 flights were delayed on Monday, plus nearly 8,000 on both Saturday and Sunday.
Almost 5,000 flights were delayed on Monday as the airline industry continues to be gripped by travel chaos over the July 4 holiday period.
4,881 flights within, into, or out of the US were delayed in one day — with a further 148 canceled — according to the tracking website FlightAware.
That was better than the weekend, however, where Saturday and Sunday each saw almost 8,000 flights delayed per day, according to FlightAware.
That followed a record-breaking Friday when 2.88 million passengers passed through Transportation Security Administration checkpoints. That surpassed the agency's initial prediction by about 60,000.
Travel chaos has been made worse by thunderstorms throughout much of the Eastern US, NBC News reported.
The busiest-ever day was followed by a deadline for airlines to retrofit their planes with updated equipment due to a planned boost in 5G signal strength.
Hundreds of planes couldn't be fitted with new radio altimeters — sensors that measure how high an aircraft is above the ground — before the July 1 deadline. That means they won't be cleared to land in low-visibility conditions.
"This represents one of the biggest – probably the biggest – foreseeable problem affecting performance this summer," US Transportation Secretary Pete Buttigieg previously warned, per The Wall Street Journal.
United Airlines has attracted attention for leading the US in disrupted flights over the past few days, FlightAware's data shows.
In a staff memo last Wednesday, CEO Scott Kirby blamed the Federal Aviation Administration (FAA) and its staffing issues for delays. This prompted Buttigieg, who oversees the FAA, to push back on criticism by calling out the airline's "internal issues," CNN reported.
But things only got worse as July 4 approached, as Kirby was forced to apologize for taking a private jet on Wednesday while 750 United Airlines flights were canceled, The Associated Press reported.
United has since said it will give 30,000 air miles to passengers affected by the disruption over the holiday.
In a statement to Insider, a spokesperson for the FAA said: "After severe storms threw a wrench into operations earlier last week, all major airlines except one recovered quickly and delays and cancellations are back to normal levels for now."
A United Airlines spokesperson referred Insider to Kirby's internal memo to staff dated July 1. He cited the thunderstorms, a need to improve United's crew technology systems, and balancing departures and arrivals at Newark, as reasons for the disruption.
Kirby added that while airlines can plan for poor weather, "United has never seen an extended limited operating environment like the one we saw this past week at Newark."