By 1915, BREITFELD - DANEK in Prague built engines under Hiero license for some model.

-The rest of the engines were originally made by Breitfeld-Danek.

-In the beginning predominated water-cooled, upright inline 6-cylinder engines.

"Perun II"

-The “Blesk” model delivered 100 CV at 1,400 rpm.

-The "Perun I" gave 180 hp at the same rpm. (fitted on the Aero A-125).

“Perun II”

-The "Perun II" delivered 240 hp and was installed on the Aero A-11 with the same characteristics.

-The 450 hp "B-D", with a "Lorraine-Dietrich" V-12 look, was made under license from the latter.

“B-D”

From Appendix 10: We found a new photo of the Perun II, at a museum in Prague.

“Perun II” (PiP)