American Airlines, the country's largest, canceled 132 flights scheduled for Thursday. It had canceled 325 flights Wednesday.
Meanwhile, Delta Air Lines also plans to ground 275 flights before the weekend.
The cancellation follows a directive from the Federal Aviation Administration (FAA), which requires the carriers to install wiring bundles in proper places according to its rule.
Earlier this month, Southwest Airlines found itself with more than 40 planes on the ground after failing to verify it had correctly inspected its Boeing 737s according to the FAA directive.
The airlines will spend several hours in performing the inspections on each plane.

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