SAN FRANCISCO (KRON) — The airport has been a headache for thousands of travelers this Memorial Day Weekend. According to the flight tracking website FlightAware, there were more than 1,500 cancellations today, adding on to the more than 5,000 flights that were cancelled Friday through Sunday.

The majority of cancellations this holiday weekend were Delta flights. Experts say they dropped the ball when it came to planning their flight schedules. The airline’s Chief Customer Experience Officer said in a statement Sunday that various factors contributed — bad weather, vendor staffing and increased COVID rates.

A travel industry analyst at Atmosphere Research Group, Henry Harteveldt, says the airline didn’t have enough pilots for the number of flights scheduled, “While a lot of airlines did pair back their Memorial Day and summer flying, Delta was not as aggressive and Delta this weekend paid the price.”

As did its passengers. Nine percent of Delta’s flights were cancelled Saturday. The airline announced on its website that it will reduce service by 100 daily departures from July to August, saying current operations are not up to Delta standards. Harteveldt says, “I think that’s responsible for Delta, I think it will allow the airline to operate the flights that it has scheduled and hopefully avoid situations like we’ve seen this weekend.”

As more people start to travel again and airlines try to make up for lost profits during the pandemic, but the experts say you need to pack your patience. Clint Henderson, with the travel website The Points Guy, says to expect more flight delays and cancellations this summer and to be your own advocate, “Know what other airlines are operating your route so that if one carrier is having a meltdown you are armed and you can say to that airline look put me on the American Airlines flight. I know that it’s leaving around the same time that the Delta flight is leaving.”

Now that airlines are scaling back their flight schedules this summer, it’s important that you check and double check your flight’s status, timing and connecting flights before leaving for the airport.