By Evie Carrick
April 02, 2019
Southwest Airlines Boeing 737 MAX aircraft are parked on the tarmac
Southwest Airlines Boeing 737 MAX aircraft are parked on the tarmac after being grounded, at the Southern California Logistics Airport in Victorville, California on March 28, 2019.
| Credit: MARK RALSTON/Getty Images

Southwest Airlines has more Boeing 737 MAX 8 aircraft than any other U.S. airline, making them the most impacted by the grounding of the aircraft.

After complying with March’s FAA requirement, the airline had removed the planes from its flight schedule through April 20, USA Today reported. Now, the interruption to Southwest’s flight schedule is expected to extend later into spring – potentially impacting late spring break travelers.

A memo sent to the airline’s pilots last week noted that Southwest will ground MAX 8s through May, and an update on Southwest's community website said there's no official end date. “While we do not have a definitive timetable for returning the 737 MAX 8 to service, we remain in communication with Boeing and the FAA and will resume 737 MAX 8 operations when authorized by the FAA.”

The airline has 34 MAX 8 aircrafts, which when in operation, accounted for less than 5 percent of their daily flights. Although the number seems small, USA Today reports that between March 13 – when the FAA first grounded the Max 8 – and March 31, Southwest had canceled 2,800 flights due to the loss of the aircraft.

Customers who booked spring travel with Southwest on a now-cancelled MAX 8 can rebook without paying any additional fees or fare differences for the same route. Travelers who choose not to reschedule can get a refund, or can use the funds toward future Southwest travel.