Around 1953 it acquired the license to build the Armstrong Siddeley Viper L-L (Long Life) under the name of "MD-30 Viper", which it tried to develop and even adding an afterburner.

"Dassault MD-R7"

-At first, it was intended for the S.O.9000 Trident, a research aircraft, and it was mounted on the S.O.9050 and on the MD-550 "Mirage I", a delta wing aircraft with two Viper MD-30 engines with afterburners.

-The MD-30 Viper -AS-V5- version on the Trident gave 745 Kgs. of thrust.

-Marcel Dassault himself developed a new engine based on the Viper AS-V10, but a third larger.

“MD-R7”

-It ran in 1956, and was called Dassault R7 "Farandole". Its power was 1,450 Kgs. of thrust.