SeaTac-based Alaska Air Group said Thursday its March air traffic jumped by 5 percent.
That figure, however, fell slightly short of the airline holding company's increase in capacity last month, 5.4 percent.
Alaska Air Group is the parent company of Alaska Airlines and Horizon Air. Its passenger traffic numbers include flights by both airlines as well has flights flown on Alaska's behalf by contract carriers such as SkyWest and PennAir.
The result of the slight mismatch between traffic and capacity growth resulted in planes slightly less full in March than a year earlier.
Alaska's flights were 87.1 percent full in March compared with 87.7 percent full in March 2013.
For 2014 through March, Alaska Air Group's traffic is up 4.8 percent compared with a capacity increase of 4.6 percent.