If a test aircraft, it is probably very light, Boeing Field is probably under noise abatement procedures and they might just be optimizing for minimal flight ti

If a test aircraft, it is probably very light, Boeing Field is probably under noise abatement procedures and they might just be optimizing for minimal flight time to get to test altitude. Would have to compare to normal test/aircraft checkout flights and not airline tracks. But no doubt they would be flight testing the reputed MCAS changes at this time so it’s a reasonable guess.