US Transport chief says unclear if 'incompetence' or bad tech to blame for groundings

Air carriers in the US canceled some 16,000 flights over the past 24 hours in the biggest such grounding since 9/11. Officials hinted that incompetence or faulty equipment, not malfeasance, is the cause.

Air carriers in the US canceled some 16,000 flights over the past 24 hours in the biggest such grounding since 9/11. Officials hinted that incompetence or faulty equipment, not malfeasance, is the cause.