File photo: CGTN

The Boeing 737 MAX, which has been grounded since March following two deadly crashes, won't be cleared to fly until 2020, the head of the Federal Aviation Administration said Wednesday.

FAA chief Steve Dickson told CNBC the agency's process for approving the MAX resumption still has 10 or 11 milestones, including a certification flight and a public comment period.

"If you just do the math, it's going to extend into 2020," Dickson said.