​Air Canada on 16 October became the latest airline to extend the removal of the Boeing 737 Max aircraft from its winter schedule, as an increasing number of carriers expect the jet will not be approved to return to service until early 2020.

Air Canada on 16 October became the latest airline to extend the removal of the Boeing 737 Max from its winter schedule, as an increasing number of carriers expect the jet will not be approved to return to service until early 2020.

"Today we are extending to February 14, 2020 the removal of the Boeing 737 Max from our operating schedule," says Air Canada executive vice-president and chief commercial officer Lucie Guillemette. "We are taking this prudent step as a result of the ongoing regulatory uncertainty about the timing of the aircraft returning to service."

Canada's largest domestic and international airline also says it will be leasing two additional widebodies in order to make up for the missing capacity.

The airline grounded its fleet of 24 Max aircraft following Transport Canada's 13 March safety notice, which was issued after two aircraft crashed in separate incidents in Indonesia and Ethiopia, killing 346 people total. Regulators worldwide pulled the Max out of service since.

In September, Air Canada said that a year might pass before that airline gets its Max fleet – which is planned to reach 50 – back in service. It has about 400 trained Max pilots – enough to operate its pre-grounding fleet of 24 aircraft, but not enough to operate additional, newly manufactured Max jets that will be available when the grounding lifts. That pilot shortage is exacerbated for Air Canada because it flies no earlier-generation 737s, meaning it has no pilots that can undergo a conversion course and fly the Max.

Air Canada is just the latest airline to revise its schedule without the aircraft amid continued uncertainty about its future. Initially, many airlines had said that they expected the grounding to end by the fourth quarter 2019, but now they are expecting the flying ban to last at least into 2020.

Southwest Airlines, which operates the largest 737 fleet, plans on a return to service in January, but earlier this week its pilots' association said it does not expect the aircraft will return to service with the carrier before February 2020.

Last week American Airlines pushed back the date on which it expects to resume Max flights to 16 January, six weeks later than it previously anticipated.

United Airlines tells FlightGlobal that it remains by its expectation that the aircraft will resume flying just after the new year. The airline has pulled Max flights from its schedule through 6 January 2020.

Differing levels of examination by regulators in different countries or regions may make the Max's return to service complicated. While the US Federal Aviation Administration could bring the aircraft back into service earlier, the European Union Aviation Safety Agency said that it intends to scrutinise the Max closely, and to conduct its own test flights, rather than rubber-stamp the FAA's approval.

EASA has said it is reviewing numerous concerns about the aircraft, including those related to the angle-of-attack indicator (specifically, the fact that the 737 has only two indicators), manual horizontal trim and flightcrew responses to emergencies.