History of Science and Engineering Annotation << Back The Flight Research Institute of the People's Commissariat of Aviation Industry and its Contribution to the Modernization of Military Equipment during the Great Patriotic War Zakharchenko A.V. During the Great Patriotic War, the Flight Research Institute (LII) played a special role in testing aviation technology. Its cooperation with other research organizations, factories, and design bureaus of the People's Commissariat of Aviation Industry contributed to the improvement of production technology for serial combat aircraft, and the introduction of new models of fi ghter, assault, and bomber aircraft. Analysis of archival documents suggests that the Institute made a signifi cant contribution to equipping Soviet aviation with radio communications and weapons. One of the areas of the team's work is the expert assessment of aircraft technology: the technical recommendations of the LII staff proved to be in demand both at aircraft factories and military units at the front. Keywords: Flight Research Institute, combat aviation, the Great Patriotic War, People's Commissariat of the Aviation Industry, fl ight tests, aerodynamics, aircraft production. DOI: 10.25791/intstg.8.2025.1567 Pp. 37-44.