Rega operates 17 rescue helicopters and three ambulance-jets. The helicopter fleet comprises six Eurocopter EC 145 machines, stationed at the four lowland bases in Basel, Zurich, Berne and Lausanne, and eleven AgustaWestland Da Vinci located at the eight mountain bases in Erstfeld, Locarno, Samedan, St. Gallen, Mollis, Untervaz, Zweisimmen and Wilderswil. At any one time, five rescue helicopters are reserve machines, which are either undergoing maintenance or being used for training purposes. The jet fleet comprises three aircraft of the same type, the Canadair CL 604 “Challenger”.