BALTIMORE (WJZ)—There’s a focus on Southwest Airlines. Federal investigators are now scrutinizing the safety of an entire fleet of planes.

Mike Hellgren is following the safety concerns after a plane developed a hole during flight.

The plane that had the hole in it had more than 30,000 takeoffs and landings, and it’s the older planes that are facing intense scrutiny.

The federal government ordered emergency inspections of older 737 jets after a terrifying Southwest flight last week where a hole ripped open in mid-flight. The plane dropped 25,000 feet in five minutes and made an emergency landing.

WJZ has learned that the jet underwent a most rigorous inspection a year ago.

“If we don’t get this under control, we are going to see more examples like this,” said Keith Franz, lawyer and aviation expert.

Towson attorney Keith Franz has handled high-profile aviation cases. He says maintenance on the airplane should be cause for concern.

“We don’t know if they are just overlooking things or doing the inspections poorly, but these problems that are slipping through are totally unacceptable,” he said.

He points to the same problem– a hole opening up on a Baltimore-bound flight two years ago—as evidence that more must be done to keep the flights safe. Particularly with Southwest, many landing and takeoffs can stress the metal.

“The FAA added additional inspectors this past year,” Franz said. “But obviously it has not shown the type of success we’re going to need to create a safe environment for an unsuspecting flying public.”

Southwest found cracks in five jets after voluntary inspections this week. They’re passing an electric current through the plane’s skin and using X-rays and ultrasound to test for microscopic cracks.

A Southwest spokeswoman seemed to shift blame to the manufacturer, telling the AP “this is a Boeing-designed airplane. It’s obviously concerning to us that we’re finding skin fatigue issues.”

Several other commercial airlines use 737s. The FAA and the NTSB are investigating and we should know more in the coming days.

Southwest has never had a fatal incident in its history.