Southwest Airlines ordered another three Boeing 737 Max simulators from flight training company CAE in the second quarter of 2019, doubling its Max simulator orders ahead of the expected lifting of the Max's global grounding.

Simulator company CAE disclosed Southwest's three-unit order on 14 August.

The airline has already received, and is now setting up, one 737 Max full-flight simulator, the carrier's vice-president of flight operations Alan Kasher told FlightGlobal last week.

Southwest expects that unit will be operational in October. It anticipates having another two Max simulators online early in the first quarter of 2020, followed by the final three in 2021, Kasher said.

Other airlines are also acquiring Max simulators following two crashes that prompted the grounding.

American Airlines has "one simulator that is in the process of being installed", and United Airlines anticipates receiving its first simulator in the first quarter of 2020, those carriers say.

Neither American nor United have said how many additional Max simulators they have on order.

Regulators grounded the 737 Max in March and have said they will lift the grounding after approving Boeing's updates to the aircraft's flight control system, and new training requirements.

Whether those requirements will include a simulator mandate remain unknown, and regulatory requirements could vary by region.

In April, Southwest chief executive Gary Kelly suggested the US Federal Aviation Administration will not require simulator time, though Boeing CEO Dennis Muilenburg has said some airlines may implement such training.

"We are not hearing that will be a requirement," Kelly said on 25 April in response to a question about possible simulator training requirements.

Kelly drew that conclusion from discussions with the FAA, Boeing and Southwest's pilots' union, he said.

Insiders have also suggested that Boeing's 737 Max software overhaul, when complete, will eliminate areas of concern that might have otherwise warranted Max-specific simulator time.

"There will likely be some selective use of simulator training," Boeing's Muilenburg said in July. "Some airlines will use simulator training as part of their recurring training. Some may want training up front before they fully return the fleet to service."

Story update: American told FlightGlobal on 11 August it has no orders for additional 737 Max simulators.