The aircraft manufacturer had hoped to have the Max flying again by the end of the year. However, Federal Aviation Administration (FAA) administrator Steve Dickson told a US congressional hearing on Wednesday (11 December) the aircraft would not be cleared to fly before 2020.

The Max model has been grounded since March following two fatal crashes in just five months.

Lion Air flight 610 came down shortly after take off from Jakarta last October. Then in March, Ethiopian Airlines flight 302 crashed en route to Nairobi.

All 346 people onboard the two flights were killed.

Boeing has for several months targeted a late 2019 or early 2020 return for the Max pending a software update for a deep-seated flight control system, thought to have been responsible for the two crashes, and new training and simulator resources for pilots.

Dickson, though, said there were several “milestones” left to complete before the FAA certifies Boeing’s efforts to get the Max flying again. “It’s going to extend into 2020,” Dickson told US news network CNBC.

As well as gaining certification from the FAA, individual aviation safety regulators around the world, such as the European Union Aviation Safety Agency, will also have to sign off the Max’s return to service in their respective territories.