The plane, the same model of which has been grounded around the world following two crashes that appeared to indicate problems with a new anti-stall system, was not carrying passengers when it was forced to make the emergency landing at Orlando International Airport.
Rather, two pilots were flying the plane to Victorville, California, where it was to have been stored. Instead, they were obliged to return to Orlando at around 3pm on Tuesday, according to the Orlando Sentinel.
“The crew of Southwest Airlines Flight 8701, a Boeing 737 MAX aircraft, declared an emergency after the aircraft experienced a reported engine problem while departing from Orlando International Airport in Florida about 2.50pm today,” the Federal Aviation Administration (FAA) said in a statement.
“The aircraft returned and landed safely in Orlando. No passengers were aboard the aircraft, which was being ferried to Victorville, Calif., for storage. The FAA is investigating.”
A Boeing spokesman said it the company was “aware of the incident and supporting our customers”.
Southwest Airlines said its pilots reported a performance issue with one of the engines shortly after takeoff. “The crew followed protocol and safely landed back at the airport,” it said.
The FAA joined regulators around the world earlier this month in grounding the planes, produced in Seattle, following two crashes – Ethiopian Airlines Flight 302 and last October’s crash of a Lion Air flight.
The Ethiopian Airlines crash earlier this month resulted in the deaths of all 157 passengers on board. In Indonesia, 189 people lost their lives.
Investigators said the two downing had “clear similarities”. They are currently investigating the recently-introduced manoeuvring characteristics augmentation system (MCAS), which is designed to stop planes form stalling on take off.