(Reuters) - A Southwest Airlines Co Boeing 737 MAX 8 heading to the California desert for parking during a global ban of the aircraft made an emergency landing on Tuesday due to an engine-related problem shortly after take-off, the carrier said.

It did not have any passengers and the issue was not related to a computer system on the 737 MAX aircraft that has come under scrutiny following two fatal crashes, one on Lion Air and another on Ethiopian Airlines, since October, the airline said.

“The crew followed protocol and safely landed back at the airport,” Southwest said in a statement.

Southwest Flight 8701 returned to Orlando International Airport just before 3 p.m. ET (1900 GMT) after pilots reported a performance issue with one of the engines, the airline said.

The flight was scheduled to fly from Orlando to a logistics airport in Victorville, California, near the Mojave desert, where Southwest began flying its fleet of 34 MAX jets for storage.

The U.S. Federal Aviation Administration grounded the 737 MAX following the two crashes but has allowed airlines to conduct flights without passengers to move planes to other airports.

A Boeing spokesman said the company was “aware of the incident and supporting our customer.”

Rather than fly to California, Southwest said the plane will be moved to an Orlando maintenance facility for review.