If aviation manufacturing is divided into eight key areas—airframes, propulsion, pneumatics, flight control, avionics, fuel, electrical power and hydraulics—India’s competence today varies considerably. Through a combination of domestic R&D and learning-by-doing in licensed production, India has slowly acquired expertise in pneumatics, fuel systems, electrical power, and hydraulics. It has gained proficiency in the manufacture of airframes and structures, though it still lags behind in advanced composites and in the development of digital flight control systems. India has yet to master propulsion, especially high-performance jet engines, which are among the most difficult technologies in the world, as well as avionics systems development and integration, which, again, remain among the most recondite capabilities,both at the level of hardware and source code.
Source: Ashley J. Tellis presentation at Carnegie