A Southwest Airlines Boeing 737 Max has made a safe emergency landing in Orlando, Florida, after experiencing an engine problem, the US Federal Aviation Administration says.
The crew declared an emergency after taking off from Orlando International Airport around 2:50pm on Tuesday local time, and returned to the airport safely.
No passengers were on board, and the aircraft was being ferried to Victorville, California, where Southwest is storing the planes.
The 737 Max was grounded in the US on March 13 after a deadly crash involving a Max in Ethiopia on March 10.
It was the second fatal crash involving the plane. US airlines are allowed to shuttle the planes but cannot carry passengers.
The FAA says it's investigating but the emergency was not related to anti-stall software that is suspected as a cause of the two fatal crashes including one last year involving a plane from Indonesia.
Southwest did not immediately respond to email and telephone messages left by The Associated Press.