Kurt Tank sized the Marut around a reheated Bristol Orpheus, the BOr.12, which with afterburner promised roughly 8,000 lbf of thrust per engine — enough to push the clean airframe toward its designed Mach 2. That engine, however, had been developed for a wider light-fighter effort and needed a substantial further investment (commonly cited at around £13 million) to bring to production. India declined to fund it, and no other government picked up the bill.

Left without its intended powerplant, the Marut entered service on two non-afterburning Orpheus 703 engines of about 4,850 lbf (21.6 kN) each — roughly 40% less thrust than the design assumed. HAL and its partners spent years chasing an alternative: a Soviet RD-9F, an Egyptian “E-300” turbojet developed at Helwan (abandoned after the 1967 war), and HAL’s own reheated Orpheus 703R, which flew in test airframes but never entered series production. The Marut therefore never reached the performance its aerodynamics allowed — the central “what if” of the whole programme.

Kurt Tank had designed the Focke-Wulf Fw 190, one of the best fighters of the Second World War, and the jet Ta 183 project. After years working in Argentina, he was recruited by Hindustan Aircraft in 1956 to create India’s first jet fighter. He inherited a design office of only around fifty engineers and virtually no test infrastructure, yet within five years had a supersonic-capable prototype flying. The Marut is, in a real sense, the last aircraft to carry the design signature of one of the great figures of Second World War aviation.

For its ground-attack role the Marut mounted four 30 mm ADEN cannon in the nose — a genuinely heavy gun battery — backed by a distinctive retractable belly rocket pack holding fifty 68 mm SNEB rockets that extended to fire and then retracted flush to preserve the aircraft’s clean lines. Four underwing hardpoints carried bombs and additional rockets, up to roughly 1,800 kg of external stores. In 1971 this concentrated firepower, combined with the airframe’s stability at low level, made the Marut an effective and popular strike platform.

The Marut was a state programme, produced in modest numbers by a young national industry and never sold on an open market, so no reliable flyaway unit price or cost-per-flight-hour figure exists in the public record. The most commonly repeated qualitative claim is that it cost more to build each Marut at home than it would have to buy a more capable foreign fighter — a judgement on the economics of self-reliance rather than a sourced accounting figure. Any precise dollar cost attached to the type should be treated as an estimate.