Jakarta, Sep 23 (IANS): Indonesian investigators have found that the design of the Boeing 737 MAX aircraft and oversight lapses were responsible for the October 2018 Lion Air crash that involved the same model, killing all 189 people onboard.

According to a draft report issued on Sunday by the Wall Street Journal, the investigators also identified pilot errors and maintenance mistakes as causal factors of the October 29, 2018 crash, adding that a final version was expected in November, reports Xinhua news agency.

The 737 MAX aircraft was globally grounded after an Ethiopian Airlines flight, using the same model, crashed in March this year killing all the 157 people onboard.

Preliminary investigation results on the Ethiopian Airlines plane discovered that the pilots followed Boeing required procedures, but could not control the flight, according to the African nation's government.

In July it was revealed that the Boeing 737 MAX planes were unlikely to restart operations until 2020 as it will take time to fix a flight-control software and complete other work.

The aircraft was currently expected to return to the air in January 2020.

American Airlines have already extended its ban on Boeing 737 MAX flights through November 2, right after United Airlines announced its decision to keep the aircraft out of schedule until November 3.