(AP) – Boeing says it has finished with its updates to the flight-control software implicated in two deadly crashes involving its 737 Max, moving a step closer to getting the plane back in the sky.

Aviation regulators still have more questions about how pilots interact with the plane’s controls under different circumstances, and Boeing says it is providing that information.

The Federal Aviation Administration, foreign regulators and airlines are reviewing Boeing’s plans for additional pilot training, the company said Thursday.

The next major step is a certification flight with FAA representatives. That flight has not yet been scheduled.

In crashes in Indonesia and Ethiopia, an automated system called MCAS mistakenly turned the noses of the planes down in response to faulty readings from a single sensor. Pilots were unable to regain control; 346 people died.

Boeing has delivered about 370 Max jets around the world, but they have been grounded since mid-March.