American Airlines Co said on Friday that a Boeing 737 MAX bound for New Jersey’s Newark Liberty International Airport pronounced a emergency after the commander shut down one motor over a potential mechanical issue.

American’s Flight 2555 from Miami with 95 travelers and six crew landed securely at Newark without episode, the airline said.

The possible issue was identified with a motor oil pressing factor or volume pointer and not the consequence of anything identified with the MCAS framework connected to two lethal 737 MAX crashes in 2018 and 2019 that provoked the plane’s 20-month establishing, it said.

Boeing Co said it knew about the American flight and the Federal Aviation Administration (FAA) said it will research.

American was the primary U.S. transporter to continue 737 MAX flights before the end of last year following the FAA’s endorsement of security refreshes by Boeing.

At the point when it cleared the plane to fly once more, FAA Administrator Steve Dickson said he was sure that the fly was protected however cautioned that in-flight mechanical issues incidentally happen with all business airplane.

“For that reason, it is inevitable that at some time in the future, a Boeing 737 MAX will turn back to its originating airport, divert, or land at its destination with an actual or suspected in-flight problem,” he said.

The FAA assesses all occasions including a U.S. carrier, he said at that point, adding: “It’s very important to differentiate between these routine events that happen with any aircraft and the acute safety issues that led to the loss of lives and grounding of the MAX.”

American took delivery from Boeing of the jet involved with Friday’s episode on Dec. 30.