The airline is undergoing emergency engine inspections.
southwest airlines boeing 737-700
Credit: Bloomberg/Getty Images

Southwest Airlines has been canceling up to 40 flights per day since it announced its voluntary inspection program on Tuesday after a mid-air engine failure caused the death of a passenger.

"Since we announced our voluntary, accelerated inspection program on Tuesday night, we have maintained minimal disruption to our operation and only needed to cancel about 40 flights each day — again on a total operating schedule of approximately 4,000 daily flights," reps for Southwest said in a statement on Sunday.

The airline announced its inspection plan for the CFM56-7B engines manufactured by CFM International that were involved in the fatal accident on Tuesday, April 17. The Federal Aviation Administration and European airline regulators also called for emergency inspections across hundreds of aircraft using the engine model on Friday, April 20.

Southwest created its inspection plan after an engine malfunction caused a piece of shrapnel to break a window during a flight scheduled to fly to Philadelphia on Tuesday, April 17, injuring seven and leading to the death of Wells Fargo executive and mother of two Jennifer Riordan. It was the first fatal incident on a U.S. passenger airline to take place since 2009.

While airline representatives said passengers should expect minimal delays or cancellations throughout this week, they're unable to provide real-time updates on the total number of disrupted flights.

“Since our operational plans entail multiple aircraft entering and exiting scheduled service during the ongoing inspection period, we are not able to provide real-time, continuous updates on total flight disruptions,” officials said in the statement.

Data from flight tracking website showed that the airline had a total of 129 cancellations and 569 delayed flights on Monday.

Customers on affected flights will receive regular updates on their flight status. Southwest said airline staff members are trying to conduct inspections overnight and utilize spare aircraft to minimize the disruptions.