Southwest AirlinesOn Tuesday, the airline cancelled 87 flights or 2% of their schedule. This is a sign it’s stabilizing its operations after weekend chaos that disrupted thousands of people’s travel plans.

Flight-tracking website FlightAware reports that the Dallas-based airline cancelled nearly 2,400 flights on Saturday. The airline attributed this to a variety of factors including its lack of staffing, such as a shortage in backup pilots and flight attendants available to help when needed.

As Southwest attempted to implement its largest schedule since April 2020, the disruptions reached their peak on Sunday with more than 1,100 cancellations.

Southwest Airlines offers a profound apology to its Customers and Employees, it said Tuesday in a statement posted on their website.

According to the carrier, bad weather conditions and problems with air traffic control in Florida caused its troubles. This led to crews and planes becoming out of order and resulting in hundreds of cancellations.

CNBC spoke with Casey Murray of Southwest Airlines Pilots Association. He said that poor planning by the airline was the reason for these problems. Due to summer disruptions, the airline already has a reduced fall schedule after crew members complained.

Southwest’s chief operational officer Mike Van de Ven was elevated to the position of president on Sunday.

The pilots union informed members on Tuesday that 2,176 Southwest flights had been cancelled over the weekend due to unavailability of crews.

Murray said that CNBC reported that the disruption caused most pilots to take up the flights.

According to union officials, October could be the most severe month in terms of pilot fatigue calls. This is compared with August when there were 633. Soon after, the airline cut its schedule.

According to the report, sick calls have increased in October compared to previous months.

“But those past Octobers weren’t affected by the chronic manning problems and cumulative fatigue that have occurred since June,” the union wrote. The sick rate in 2021 is steadily increasing as crews are worn down from the operation. That statistic is supported by fatigue data.”