LAWA used Plant 42's facilities in past years for scheduled air carrier service. In 1990, America West Airlines was operating nonstop service to Las Vegas and Phoenix with de Havilland Canada DHC-8 Dash 8 turboprops. However, this America West service lasted less than a year. Also during the 1990s, several commuter airlines used the Palmdale Regional Airport passenger terminal sited on Plant 42. These air carriers included SkyWest Airlines operating as the Delta Connection flying Fairchild Swearingen Metroliner propjets nonstop to LAX in the early 1990s and Mesa Airlines operating as United Express flying Beechcraft 1900C turboprops to LAX in the mid 1990s. Both airlines operated up to six round trip flights a day between the airport and LAX before ceasing all service. This civilian terminal was unused from 1998 to 2004; on December 29, 2004, civilian use resumed when Scenic Airlines began scheduled service to North Las Vegas, Nevada, although that service officially terminated in January 2006. United Airlines regional airline affiliate United Express operated by SkyWest then began daily service to San Francisco International Airport (SFO) in June 2007, first with Canadair CRJ-200 regional jets, which were then replaced with Embraer EMB-120 Brasilia turboprops. However, United Express then suspended all flights on the SFO-PMD route in December 2008 upon the expiration of grants that subsidized this scheduled air service.