Southwest has grounded nearly 20% of their fleet.
This, after they failed to perform mandatory inspections, a spokeswoman for the low-cost carrier reportedly said, late Tuesday.
The move affects the carrier’s Boeing 737 planes and 90 of its flights have so far been cancelled.
The Dallas-based carrier is the world’s largest operator of Boeing 737 jets. The system at issue — known as the “standby hydraulic system” — is used to control the rudder if the main system to steer the aircraft fails.
Southwest Airlines Co. is a major U.S. airline and the world’s largest low-cost carrier, headquartered in Dallas, Texas. The airline was established in 1967 and adopted its current name in 1971.
