 By the 1970s Meigs Field became a critical facility for aeromedical transport of patients and transplant organs to downtown hospitals as medical transportation technology modernized.Corporate aircraft also used the airfield including Cessna Citation and Dassault Falcon 10 business jets, and Beechcraft King Air and Grumman Gulfstream I business propjets.The Main Terminal Building was operated by the Chicago Department of Aviation and contained waiting areas as well as office and counter space.