Cal Fire began using contractor-owned helicopters for fire control in the mid-1960s. Bell 47, Hiller FH1100, Bell 206 JetRangers and Aerospatiale Alouettes were used the most through the 1970s. The helicopters were located at Cal Fire facilities which protected high value timberlands and critical watershed areas generally in Northern and Central California with one located at Ryan Field in Southern California. The helicopter began playing an increasing role in the Cal Fire's Initial Attack strategy during the late 70s. In 1978 three Bell 205 medium helicopters were hired in addition to the standby helicopters. One helicopter was located at the Howard Forest, Mendocino Ranger Unit Headquarters. The other two were located at Hemet/Ryan Field and the Monte Vista, San Diego Ranger Unit Headquarters. Each of the medium helicopters was assigned 11 person helitack crews. Unfortunately, in the mid to late 1970s Cal Fire experienced an increased accident rate throughout the helicopter program. Five accidents involving contractor-owned Bell Jet Rangers occurred in 1979.