Federal Aviation Administration Chief Steve Dickson completed a two-hour evaluation flight at the controls of a Boeing 737 Max on Wednesday as part of the final stages of a recertification process after two fatal crashes.
The 737 Max was grounded in March 2019 after deadly crashes in Ethiopia and Indonesia killed 346 people over a five-month period.
In both crashes, a flawed control system known as MCAS, triggered by faulty data from a single airflow sensor, repeatedly and forcefully pushed down the jets' nose as pilots struggled to intervene.
Since then, Dickson made known he wouldn't approve the airplane until he flew it himself and was convinced of its safety.
On Wednesday, Dickson, a former military and commercial pilot, flew together with other FAA and Boeing pilots from King County International Airport - also known as Boeing Field - in the Seattle area.
During the flight, he tested a number of Boeing design and operations upgrades intended to prevent similar disasters.
If all goes well, the 737 Max could be back in U.S. skies before the end of the year.
Meanwhile, the U.S. House Committee on Transportation and Infrastructure on Wednesday unanimously approved bipartisan legislation to reform the FAA's aircraft certification process in the wake of the 737 Max crashes.