An engine cover rips off a Southwest Airlines Boeing 737, forcing an emergency landing

• A Southwest Airlines flight returned to Denver after an engine cover ripped off mid-flight.
• The 737-800 aircraft involved is a previous-generation variant, not the recently scrutinized Max 9.

A Boeing 737 operated by Southwest Airlines had to turn around mid-flight after an engine cover ripped off on Sunday.

Southwest Airlines told Business Insider in a statement that Flight 3695 returned to the Denver International Airport and landed safely after experiencing a "mechanical issue." The airline said its maintenance team is reviewing the aircraft.

"Our Customers will arrive at Houston Hobby on another aircraft, approximately three hours behind schedule," Southwest said in the statement. "We apologize for the inconvenience of their delay, but place our highest priority on ultimate safety for our customers and employees."

Video of the incident shared online shows a section of the plane's engine cowling — a panel that covers the engine — tearing away from the aircraft.

In January, a part of the fuselage on Alaska Airlines Boeing 737 Max 9 fell off mid flight, raising concerns about Boeing’s quality control. The Max 9 is a different model from the Southwest 737- 800 that lost its engine cowling.”

The FAA said in a statement at the time that each plane would have to undergo an eight-hour safety inspection before it's allowed to carry passengers again.

Boeing Chairman Steve Mollenkopf has reached out directly to several airlines following the company's recent struggles, Bloomberg reported. Mollenkpf's move came after Ryanair CEO Michael O'Leary said that Boeing showed a "lack of attention to detail."

"In 2022 and 2023, we were finding little things like spanners under the floorboards, in some cases, seat handles missing, things like that," O'Leary told CNN in March.

The FAA told Business Insider that it is investigating the incident. Boeing referred BI to Southwest Airlines when reached for comment on Sunday.

The Alaska Airlines blowout in January has brought increased scrutiny around Boeing's quality control in the following months.

Following the incident, the Federal Aviation Administration announced it would investigate Boeing's manufacturing process.

The FAA revealed in March that its probe found "multiple instances where the companies allegedly failed to comply with manufacturing quality control requirements." The agency also noted that it had found 27 areas in Boeing's safety procedures that were insufficient.

After the Alaska Airlines incident, several key executives, including Boeing CEO Dave Calhoun, announced that they would resign.

In a press release, the plane manufacturer also vowed to implement more inspections on the production line and change its quality practices.

Correction: April 8, 2024 — An earlier version of this story failed to identify the plane model involved in the incident, it is a 737-800, which is different than a 737 Max 9 or other variants. Also, the door plug that fell off of an Alaska Airlines plane was not covering where a previous door had been; it is where a door could be. It is sealed at the factory.