That's about 1 percent of Dallas-based Southwest's daily schedule of nearly 4,000 flights. The airline encouraged passengers to check their flight status. "We anticipate minimal delays or cancellations each day due to the inspections," Southwest said in a written statement.
Both airlines last week, in advance of the Federal Aviation Administration's official release of an emergency airworthiness directive, said they would accelerate the inspections.
The FAA on Friday issued the anticipated directive requiring airlines to inspect fan blades on certain engines within 20 days. The directive draws from information gathered in the investigation of Southwest's engine failure last Tuesday. The FAA said the inspection requirement is estimated to affect 352 engines in the United States and 681 engines worldwide.
The CFM56-7B engine that blew on the Southwest flight showed evidence of “metal fatigue,” according to the National Transportation Safety Board. That engine model is on all of Southwest’s 737-700s and 737-800s, which make up the vast majority of Southwest’s fleet.