The new version of the advanced trainer Praga BH-41 was the Praga E-141 with Diesel engine ZOD-260. This was not very succesfully and new version Praga E-241 with Walter Pollux II engine first flown in 1936 year. Aicraft was designed from ing. Jaroslav Slechta. Total was produced about 80 machines, which was used in Czechoslovak army to March 1939 year. In war years were flown in Slovakian A.F. as trainer and reconnaissance as operational on the Eastern front. Luftwaffe also used some machines as advanced trainers in A/B schools.