Dvadesetprvi Maj in Belgrade was founded in 1948, taking advantage of the previous aviation engine factory. They started manufacturing Walter engines under license.

-They projected engines of their own design for light airplanes of the Yugoslavian Armed Forces including a 53 hp turboshaft in collaboration with the University of Belgrade.

-After a period of diversification, a turbine engine division was made and they began to manufacture the Turbomeca "Palas".

-In 1973 they made the "Astazou" III and XIV-M, as well as components for the Viper turbojet engines for their own aircraft.

From Appendix 10: At the Belgrade museum there is a 6-cylinder, inverted, inline DMB-6R engine with gearbox.

“DMB-6R engine” (Foto Evzen)

“From the other side”

-DMB is Dvadestprvi-Maj-Beograd.

-"Rakovica Turbomekinej" (See) is located in Rakovica. (Now it is a city of Croatia)

"D4-6R"