More than three decades after it was cleared for development, the “Tejas” Light Combat Aircraft — India’s first indigenously built fighter jet, was inducted into the air force. The aircraft, developed by the state-run Hindustan Aeronautics Limited (HAL), will eventually replace the country’s aging squadron of the Russian-made MiG-21s — planes that have, for the past 50 years been the backbone of the air force’s fleet but have been plagued with a patchy safety record.