Alaska Airlines has started flying Boeing 737 Max 9s again for the first time since they were grounded after a panel came off one of its planes on January 5.
In a press release, the air carrier indicated that it had completed the inspection of a first group of planes.
A Max 9 was able to be used for a flight from Seattle to San Diego on Friday afternoon.
On Wednesday, the United States Federal Aviation Administration (FAA) approved the inspection and maintenance process necessary for the return of Max 9 aircraft.
Alaska Airlines technicians began their inspections that night, the airline said, and they are expected to continue through the end of next week.
Inspections can take up to 12 hours by plane.
“Each of our 737 Max 9s will only be returned to service once rigorous inspections are completed. Each aircraft must be deemed airworthy in accordance with FAA requirements,” the carrier said in a statement released Friday.
United, another airline, also plans to resume use of the Max 9s on Sunday, but a company spokeswoman said the planes could be used as spares as early as Saturday.
Alaka Airlines and United are the only two US airlines to operate this particular model of the Boeing 737.
Alaska Airlines grounded its 65 Max 9 planes a few hours after the incident in which a door opened and detached from the cabin in mid-flight, about 4,900 meters above Oregon.
This type of stopper holder is used to lock a door when the number of emergency exits is sufficient depending on the number of seats in the aircraft.
The FAA grounded all Max 9s in the United States the day after the incident, which caused no serious injuries.