SeaTac-based Alaska Air Group, parent company of Alaska Airlines and Horizon Air, saw its passenger traffic jump by 9.5 percent last month, but its capacity grew slightly faster than its traffic increases resulting in planes being fractionally less full than a year earlier.
The airline holding company reported that it filled 87.7 percent of its seats with paying passengers in March, down from 87.9 percent in March 2012.
Alaska’s traffic increases flew in the face of industry trends. Delta Air Lines, US Airways, and United Airlines all reported weaker traffic in March. They attributed that slackening demand in part to …