Boeing conducted another test flight of the troubled 737 Max jet on Monday. The flight landed safely at Seattle's Boeing Field shortly after 5 p.m.
A spokesperson for Boeing clarified that it was a safety test flight, not a certification flight.
"These non-commercial test flights - with a small test team on board - will exercise short- and long-haul flights, seeking out weather and altitude conditions that will help satisfy specific test conditions for the updated software," Boeing's Bernard Choi said in a statement.
The flights began on Feb. 7 and will land at various airports with the updated software.
The 737 Max was grounded in March 2019 after crashes in Indonesia and Ethiopia killed 346 people.
Boeing is overhauling flight-control software that played a role in the two crashes, pushing the noses of the planes down based on faulty sensor readings.
Choi added, "With safety as our highest priority, we are working with regulators to appropriately address all certification requirements and safely return the 737 MAX to service."
VIEW | Boeing 737 Max coverage