Mil Mi-3

The Mil Mi-3 was a Soviet light utility helicopter project of the 1960s, conceived by the Mil design bureau as a larger and heavier development of the Mi-2. Full-size mock-ups of Mi-2 derivatives were ready by 1964, but calculations showed that the Mi-2 engines would leave the enlarged machines underpowered, and the project was dropped for lack of suitable engines. The designation was also attached to a later Polish and Soviet plan for a bigger helicopter based on the Mi-2 that could replace the Mi-4, which ended when the Polish side chose to build its own PZL W-3 instead. An earlier, unrelated Mi-3 was a Mi-1 improved with a four-bladed main rotor.