FLORIDA >> A Southwest Airlines Co. 737 Max aircraft being flown to storage was forced to return to a Florida airport today after experiencing an engine problem, the carrier said.

The engine “performance issue” occurred shortly after the Boeing Co. plane left Orlando International Airport at about 2:50 p.m. local time, said Brandy King, a spokeswoman for Southwest. The fault had “absolutely no relation” to the flight-control issue that prompted U.S. regulators to ground all 737 Max aircraft on March 13.

The crew of Southwest Flight 8701 declared an emergency and landed safely in Orlando, the Federal Aviation Administration said in a statement. The FAA said it’s investigating the incident. The Max aircraft was being flown to storage in Victorville, California, and only the pilots were on board, Southwest said.

Aviation officials in several countries grounded the Max after the plane’s Maneuvering Characteristics Augmentation System, or MCAS, caused a Lion Air jet to repeatedly dive on Oct. 29 until pilots lost control and it crashed. An Ethiopian Airlines 737 Max followed a similar flight path before it slammed into the ground on March 10. The two crashes killed 346 people.

A U.S. Senate panel is scheduled to hold a hearing Wednesday on the two disasters and federal oversight of air safety.

Boeing fell less than 1 percent to $368.35 after the close of regular trading. The shares dropped as much as 3.1 percent following initial reports of the Southwest plane’s emergency landing.