In 1939-1941 Lyulka elaborated the design for the World's first turbofan engine, and acquired a patent for this new invention on 22 April 1941.

Although several prototypes were built and ready for state tests, Lyulka was forced to abandon his research and evacuate to the Ural mountains as the Great Patriotic War began with the Nazi invasion of the Soviet Union.

In the 1970s, Pavel Sukhoi asked Lyulka to design a new engine with unorthodox characteristics for installation on the projected Su-27.

To this day, the patent for double jet turbofan engines widely used in all sectors of the world's aviation belongs to him.

The AL-31 alone has become the cornerstone for various international developments in both civilian and military sectors, now undertaken by NPO Saturn, the heir to Lyulka's OKB.