Boeing Chief Executive David Calhoun, shown at the White House earlier this month, said production on the 737 MAX will ramp back up ahead of mid-2020

Boeing plans to begin ramping up 737 MAX production ahead of winning regulatory approval to resume service on the plane, Chief Executive David Calhoun said Wednesday.

Calhoun, addressing reporters during an hour-long conference call, dismissed speculation that the MAX could be grounded permanently.

He instead described a production ramp-up plan that will begin some months before mid-year, with the company's engaged "well before that."

The remarks came one day after Boeing officially pushed back until mid-2020 the timeframe for winning regulatory approval for the MAX, which has been grounded since March following two .

Boeing this month suspended production on the MAX, its top-selling plane, citing uncertainty on when regulators will clear the plane to resume service.

Calhoun said Tuesday's new timetable followed a decision earlier this month to endorse simulator training to MAX pilots and reflected a desire of airline customers for a more realistic schedule after Boeing missed MAX target dates repeatedly in 2019.

"I'm not trying to be conservative," he said. "I'm simply trying to put a reality-based set of numbers out there."

Calhoun reaffirmed his commitment to the MAX, saying "I believe in this airplane" and pointing to from pilots.

While there were multiple factors behind the two crashes, Calhoun highlighted in particular a wrong assumption by Boeing and regulators that pilots could quickly respond to the malfunctioning of a flight handling system and reassert control over the plane.

That system, the Maneuvering Characteristics Augmentation System, has singled out as a central factor in both the Lion Air and Ethiopian Airlines crashes, which together claimed 346 lives.

Calhoun predicted the flying public would come around on the MAX after it gets a rigorous once-over from regulators and then pilots.

At the end of the process, "when pilots get on that airplane and support that airplane, I believe customers will follow," he said.