[en] Six possible successive two-delta excitation mechanisms for pion-induced non-analog double charge exchange transition on the targets ¹⁶O and ¹²C are suggested. In the framework of the model proposed here the angular distributions of 164 MeV for ¹²C and 120, 164 and 200 MeV for ¹⁶O have been evaluated and compared with the existing data. Our results are in good agreement with experimental data available, and strongly indicate that the non-analog transitions ¹⁶O(π⁺, π^-)¹⁶Ne_(g.s.) and ¹²C(π⁺, π^-)¹²O_(g.s.) proceed basically through the double delta isobar excitation on a nucleon, and the dominant process is the so-called successive Δ mechanism. (orig.)