Southwest Airlines grounds 128 planes for overdue inspections of backup hydraulic systems

Southwest Airlines says it has grounded 128 planes after failing to inspect backup hydraulic systems used to control the rudder if the main system fails.

Southwest says it has canceled 90 flights so far. The grounding covers about one-fifth of its fleet.

The airline said Tuesday night that after discovering the inspections had been skipped, it immediately notified federal safety regulators and began checking the planes.