Bucking the trend toward outsourced MRO, U.S. regional carriers are expanding in-house facilities to handle an increasing amount of their maintenance needs, particularly on growing fleets of Embraer 170/190 family aircraft and next-generation versions of Bombardier CRJ700 and CRJ900 jets.

U.S. regionals' fleets are extensive, and their aircraft are flown intensively, making maintenance key. A growing number of larger regionals operate fleets ranging from 150 aircraft to many hundreds, eclipsing the fleets of so-called "major" airlines. Most regionals perform virtually all of their own line maintenance and the bulk of their major maintenance as well, in extensive facilities around the U.S.

Reasons include the regionals' expertise in their aircraft and their "more regionalized" short-to-medium range networks, making hubs and maintenance bases, with spares provisioning, never far away--and their ability to service aircraft overnight.

Examples of regional carriers expanding in maintenance include SkyWest Airlines at Colorado Springs (the firm has 436 aircraft and no fewer than 13 other maintenance bases, with the largest in Salt Lake City); Mesaba at Des Moines; Compass Airlines at Louisville International; Republic in Columbus, Ohio; and American Eagle, at the Northwest Arkansas Regional Airport near Bentonville.