Southwest plane hole might have been metal fatigue

That’s the preliminary possibility of the National Transportation Safety Board, about the cause of the fuselage hole in the Southwest Airlines Nashville-Baltimore flight July 12. The NTSB said the hole showed no sign of “significant corrosion or obvious pre-existing mechanical damage.”

All very preliminary, to be sure. But, Southwest has to be hoping this is NOT the case. If metal fatigue turns out to be the cause, that means even tighter Federal Aviation Administration scrutiny of Southwest’s plane inspections.

Beyond that, it exposes the flip side of Southwest’s taunted one-plane-fits-all-routes efficiency. If this is a problem with 737-300s, it’s a big problem for the airline.

Again, all very preliminary.