 Unlike either the original DB 605 or the Rolls-Royce Merlin, the torque of this substitute engine was extremely high resulting in a high fatality rate from these aircraft.Production ended in 1948, and the Czechoslovak National Security Guard retired the last of the S-199s in 1957.Post war, in addition to the Spanish and Czechoslovakian Air Forces, both Finland and Switzerland continued to use the Bf 109 operationally until the late 1950s.