“Full technology transfer in fighter jet engines is like handing over the crown jewels of aerospace engineering,” one top Indian defense official said last year. That crown is now in India’s hands.

Aerodynamically, the engines can run in disturbed airflow from the wings and fuselage, with potential loss of efficiency. Nevertheless, for most private jet mission profiles high-speed long-range ...

Adaptive cycle engines are specially designed to alternate between efficiency and raw power—extending an aircraft’s range without compromising on speed during engagements. The modern fighter jet is ...