Imperial Airlines

In a brief alliance with Borrego Springs, CA based Sun Aire Lines in the mid-1970s a Swearingen Metroliner "Metro II" turboprop was placed on the route.The arrangement proved problematic and the two lines went their separate ways, with the high-time Queen Air pressed back into service between Imperial and San Diego.By 1976 there were five or six round trips flown Monday through Friday, none on the weekends, the first departing Imperial at 6 a.m. on the 36-minute flight, with service ending each night just before 8 p.m. back in the "Valley."For several years circa 2015 SeaPort Airlines utilized the single engine turboprop Cessna Caravan 208 configured with nine seats and provided infrequent service.According to the airline's route map, Imperial was serving the following destinations in California in September 1984:[4] Imperial was operating a mix of Swearingen Metroliner and Embraer EMB-110 Bandeirante turboprops as well as smaller Cessna 402 and Cessna 404 prop aircraft during the early 1980s[5] and had earlier operated Beech 18 prop aircraft.