High Quality Content by WIKIPEDIA articles! The Indian Air Force started a massive modernization and up-gradation program to replace/upgrade its aging and outdated equipment since the late 90’s to advanced standards. For that reason it has started procuring and developing aircraft, weapons, associated technologies, and infrastructures. Some of these programmes date back to the late 80’s. The primary focus of upgradation is to replace the aircraft procured from the Soviet Union that form the backbone of the Air Force.