Engine cover of Southwest Airlines plane comes off during takeoff

The Federal Aviation Administration on Sunday said it will launch an investigation after the engine cowling of a Southwest Airlines plane fell off during takeoff in Denver and struck the wing flap. The cowling is the protective cover over the plane's engine.

Southwest Airlines Flight 3695 returned safely to Denver International Airport around 8:15 a.m. local time on Sunday after the pilot reported the incident, the FAA said. The plane was headed to William P. Hobby Airport in Houston.

In a statement, Southwest Airlines said it is working to get customers on their way to Houston on another aircraft after Flight 3695 landed safely in Denver and that its maintenance teams are reviewing the aircraft.

Frank Sanger, who was on the flight, expressed shock after getting a glimpse of the plane’s state when he deplaned.

“You could see the jet engine had a panel stripped away, all the way around,” Sanger said in an interview that aired Monday on NBC’s “TODAY” show.

This is the second incident in recent days involving a reported malfunctioning of equipment on a Southwest Airlines flight. The FAA is investigating a reported engine fire before takeoff at Lubbock Preston Smith International Airport on Thursday.

United Airlines flights have also recently faced safety issues, with eight incidents having been reported in the last two weeks.

Sasha Johnson, the vice president of corporate safety at United, said in a statement that the FAA will be playing a larger role in the company.

"Over the next several weeks, we will begin to see more of an FAA presence in our operation as they begin to review some of our work processes, manuals and facilities," Johnson said.

These incidents come on the heels of skyrocketing scrutiny the airline industry continues to face, with Boeing under investigation by the FAA, Department of Justice and National Transportation Safety Board, following the Alaska Airlines door plug blowout.