Southwest Airlines chief executive Gary Kelly expects the airline's Boeing 737 Max fleet to be grounded beyond 1 October, following new issues uncovered with the aircraft by US regulators.

The Dallas-based carrier had recently extended its 737 Max cancellations through 1 October, but Kelly told employees in an internal update that additional problems with the aircraft will result in a longer delay in the aircraft returning to service.

"I’m sure that this will cause us to have to take the Max out of schedule beyond October 1," says Kelly in the update, according to Southwest.

He did not provide a timeline for when the aircraft will return to service.

"We’ll also see what other modifications we might need to make to our plans for this year because it’s obviously extending well beyond what I had hoped," Kelly adds.

Southwest had operated the largest fleet of 737 Max aircraft prior to the global grounding, with 34 737 Max 8 aircraft in service.

The low-cost carrier had initially removed the 737 Max from its schedules through 5 August, before extending this to 2 September and most recently 1 October.

The most recent cancellation removed about 150 daily flights – or less than 4% – of the airline's peak-day schedule of more than 4,000 flights.

Source: Cirium Dashboard